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Concept Functionblocks for Heating, Ventilation & Air Condition

1. 78 00 Glossary Here you will find a short description of the terms 00 79 80 00 Glossary 984LL Refer to Ladder Logic 984 A Active window The window selected at present Only one window can be active at any given time When a window becomes active its title bar changes color to differentiate it from the other windows Non selected windows are inactive Actual parameter Currently connected input output parameter Addresses Direct addresses are memory areas in the PLC They are located in State RAM and can be assigned to input output modules ANL_IN ANL_IN represents the data type analog input It is used for analog value processing The data type is automatically assigned the 3x references specified in the I O map of the configured analog input module Therefore only unlocated variables can be assigned ANL_OUT ANL_OUT represents the data type analog output It is used for analog value processing The data type is automatically assigned the 4x references specified in the I O map of the configured analog output module Therefore only unlocated variables can be assigned ANY In this version ANY includes the data types ANL_IN ANL_OUT BOOL BYTE DINT INT REAL UDINT UINT TIME and WORD as well as data types derived from those ANY_BIT In this version ANY_BIT includes the data types BOOL BYTE and WORD ANY_ELEM In this version ANY_ELEM inclu
2. BOOL REAL REAL REAL REAL PARA_CC3 CC3_VAC SP Y1 CV Y2 PV1 Y3 PV2 NORM MAN_CTR MAN_SEQ YMAN_PC Y1_PC YMAN1_PC Y2_PC YMAN2_PC Y3_PC YMAN3_PC ERR1 PARA ERR2 REAL REAL REAL REAL REAL REAL REAL REAL 00 25 CC3_VAC 2 2 Parameter Specifications Table 1 CC3_VAC Parameter Data Type Meaning SP REAL Setpoint CV REAL Command variable PV1 REAL Actual value P controller PV2 REAL Actual value PI controller NORM BOOL Basic setting MAN_CTR BOOL MANUAL for controller MAN_SEQ BOOL MANUAL for sequences YMAN_PC REAL Total manual manipulated variable as a for controller YMAN1_PC_ REAL Individual manual manipulated variable as a 1st sequence YMAN2_PC_ REAL Individual manual manipulated variable as a 2nd sequence YMAN3_PC_ REAL Individual manual manipulated variable as a 3rd sequence PARA PARA_CC3 Parameter structure Y1 REAL Manipulated variable Output variable 1 Y2 REAL Manipulated variable Output variable 2 Y3 REAL Manipulated variable Output variable 3 Y1_PC REAL Manipulated variable Output variable 1 as a Y2_PC REAL Manipulated variable Output variable 2 as a Y3_PC REAL Manipulated variable Output variable 3 as a ERR1 REAL Control difference P controller ERR2 REAL Control difference PI controller 26 00 C
3. G Generic Data Type A data type representing more than one type of data Global Derived data types Global Derived data types are available in every Concept project they are deposited in the DFB directory immediately below the Concept directory Global DFBs Global DFBs are available in every Concept project they are deposited in the DFB directory immediately below the Concept directory Global Macros Global Macros are available in every Concept project they are deposited in theDFB directory immediately below the Concept directory Groups EFBs Some EFB libraries e g the IEC library are subdivided into groups This makes it easier to find the EFBs especially in very large libraries 90 22 Glossary H Hot Standby A hot standby system consists of two identically configured PLC units that are communicating with each other via hot standby processors If there is a failure of the primary PLC the secondary PLC will assume the control check Under normal conditions the secondary PLC assumes no control functions it only checks status information to detect errors Icon Graphical display of various objects in Windows e g drives application programs and document windows Identifier refer to IEC naming convention IEC 1131 3 International Standard Programmable Controllers Part 3 Programming Languages March 1993 IEC naming conventions Identifier An identifier is a string of letters numbers a
4. 00 CC2_VAC 3 4 Output Parameters The CC2_VAC outputs Y1 and Y2 are available in real or percentage form Y1 Y2 Y1_PC and Y2_P2 The percentage values specified for the manual control of outputs YMAN_PC YMAN1_PC and YMAN2_PC refer to the specified range of the appropriate output For example the variable YMAN_PC sets the total output of the PI_VAC basic function block The range of this output is specified by the parameters YMIN 0 and YMAX 100 The variables YMAN1_PC and YMAN2_PC set the outputs of the two SEQ_VAC blocks the ranges of which are specified by their corresponding ordinate vales Y1 Y2 where Y1 and Y2 refer to the SEQ_VAC ordinates not the actual outputs Y1 and Y2 of the two SEQ_VAC blocks It is important to note that the smaller value of Y1 and Y2 is always equated to 0 and the greater value to 100 In other words the percentage value is related to the size of the output variable Y irrespective of its direction Y1 lt Y2 gt 0 100 Y1 Y2 Y1 gt Y2 gt 0 100 Y2 Y1 For more information on the operation of the SEQ_VAC block please refer to the respective description see page 49 00 23 CC3_VAC CC3_VAC Cascade controller for air conditioning with 3 outputs Brief description The CC3_VAC module is a cascade controller used to provide temperature or humidity control of the inlet air to a room It consists of a P only outer loop which uses the room tem
5. SP y1 REAL REAL cv y2 REAL REAL pv1 REAL pv2 BOOL NORM BOOL MAN_CTR BOOL MAN_SEQ REAL YMAN_PC y1_PC REAL REAL YMAN1_PC y2_pcr REAL REAL YMAN2_PC ERR1 REAL PARA_CC2 PARA ERR2 REAL 2 2 Parameter Specifications Table 3 CC2_VAC Parameter Data Type Meaning SP REAL Setpoint CV REAL Command variable PV1 REAL Actual value P controller PV2 REAL Actual value PI controller NORM BOOL Basic setting MAN_CTR BOOL MANUAL for controller MAN_SEQ BOOL MANUAL for sequences YMAN_PC REAL Total manual manipulated variable as a for controller YMAN1_PC REAL Individual manual manipulated variable as a for 1 Sequence YMAN2_PC_ REAL Individual manual manipulated variable as a for 2 Sequence PARA PARA_CC2 Parameter structure Y1 REAL Manipulated variable Output variable 1 Y2 REAL Manipulated variable Output variable 2 Y1_PC REAL Manipulated variable Output variable 1 as a Y2_PC REAL Manipulated variable Output variable 2 as a ERR1 REAL Control difference P controller ERR2 REAL Control difference PI controller 00 CC2_VAC Table 4 PARA_CC2 Element Data Type Meaning SP_SPCV BOOL Setpoint setpoint command variable P controller YMAX1 REAL Upper limit manipulated variable YMIN1 REAL Lower limit manipulated variable GAIN1 REAL Controller gain PROP1 REAL Proportional value PREF1
6. State RAM state memory is the memory location for all variables addressed in the user program through references direct representation For example input bits output holding bits input registers and output holding registers are located in State RAM Status bits There is one status bit for each node with global input specific input or output of peer cop data If a defined group of data was successfully transferred within the set timeouts the corresponding status bit will be set to 1 If not this bit is set to 0 and all data belonging to this group to 0 will be deleted Step SFC language element A situation in which the behavior of a program with respect to its inputs and outputs follows a set of rules defined by the associated actions of the step Step Name The step name is used to uniquely identify a step in a program organization unit The step name is automatically created but it can be edited The step name must be unique throughout the program organization unit or an error message will occur The automatically created step name always has the structure S_n_m S step n number of section consecutive number m number of step in the section consecutive number Structured Text ST ST is a text language as per IEC 1131that displays operations such as invocations of function blocksfunctions conditional execution of instructions repeat of instructions etc through instructions Structured variables Variables t
7. Invocation The process that initiates the execution of operations specified by an FFB type The instruction can be preceded by a label that is followed by a colon If there is a comment it must be the last element in the line I O map The I O stations of the different central processing units are configured in the I O map J Jump An element of the SFC language Jumps are used to skip over areas of the sequence 22 93 Glossary K Keywords Keywords are unique character combinations that are used as specific syntactic elements as defined in Appendix B of IEC 1131 3 All keywords used in the IEC 1131 3 and therefore in Concept are listed in Appendix C of the IEC 1131 3 These listed keywords may not be used for any other purpose such as for names of variables sections instances etc L Ladder diagram Refer to Ladder Diagram LD Ladder Logic 984 LL Ladder Diagram LD Ladder diagram is a graphical programming language as per IEC 1131that orientates itself optically at the rungs of a relay ladder diagram Ladder Logic 984 LL In the terms Ladder Logic and Ladder diagram the word ladder is a reference to technique In contrast to a schematic diagram a ladder diagram is used by electricians to draw a circuit using electrical symbols and intended to show the sequence of events not the actual wires that connect the parts A common user interface to direct the actions of programmable controllers allow
8. delay Instance name Function number Operation Operand e g SW_VAC Formal parameter Actual parameter Variable element of a e g SP CV SPRT multi element variable Literal direct address e g IN DEGREE OUT 1 00005 FBI_2_2 2 18 yac 7 SW_VAC IN D gt SP SPRT gt OUT DEGREE gt CV 1 00005 gt SP_SPCV 1 1 1 Operation The operation determines which functionality is to be executed by the FFB e g shift register conversion operations 00 Parameter assignment Operand The operand determines what the operation will be executed with In FFBs it consists of formal parameter and actual parameteralparameter und Aktualparameter Formal parameter Actual parameter The formal parameter is a placeholder for an operand During parameter assignment the formal parameter is allocated an actual parameter actual parameter The actual parameter can be a variable a multi element variable an element of a multi element variable a literal or a direct address Conditional Unconditional Call Each FFB has the capability of a conditional or an unconditional call The condition will be evaluated via a prelink of the EN input m EN ENABLE conditional call the FFB will only be executed when ENABLE is set m EN hidden unconditional call FFB is always executed Not
9. PV PV YMAN2_PC YMAN_PC SEQ_VAC lje Y2 A Y2_PC 7 Lae NORM Module control MAN_CTR MAN_SEQ PARA_UC2 JWT Module parameters 62 00 UC2_VAC 3 2 3 3 Basic Operation The setpoint for the UC2_VAC function block is fed to the Pl controller via the summer winter setpoint compensation block SW_VAC description see page 54 The output of the SW VAC block is fed to the setpoint input of the PI controller The Pl controller output is fed to 2 sequence output blocks SEQ_VAC The Pl controller output can be maintained within minimum and maximum limits by using the Pl controller output limits YMAX1 and YMIN1 Manual Operation There are 3 possible modes of manual operation which are specified by setting the mutually exclusive NORM MAN_CTR and MAN_SEQ parameters NORM mode NORM 1 The output of the Pl controller output is set to zero The zero value is fed to the output sequences that are active in NORM mode As a result the actual values of Y1 and Y2 that are output to the control actuators will depend on the output sequence parameters In the case where the controller output limits YMIN2 and YMAX2 have been set to values that do not enclose zero the output will be set to the value of YMIN2 and YMAX2 that is closest to zero In other words Y YMAX2 if YMAX2 lt 0 AND YMIN2 lt 0 Y YMIN2 if YMAX2 gt 0 AND YMIN2 gt 0 Again the actual values of Y1 and Y2 that are output to the c
10. Schneider Automation You are not authorized to translate this document into any other language 1999 2003 Schneider Automation GmbH All rights reserved Contents Contents ADOUL oc asst crete ead oeeet dered ae aed a ae i eio na ewe eae 2 1 Symbols USed ssi pe ives tae ee Yee Sede Silas be eee ee TEE 2 Terms and abbreviations used ee eee tenes 3 Additional documentation 0 cece eee teens 3 Note on validity 062 22 Ayat aed cee ee Gee aaa hae cin hae a eed 3 Parameter assignment 00 cece cece eee eee eee 5 General Information simi eak iiai e daei a a e a eens 6 Operations reaboni a A aa ee ete eis ha hie E alae 6 Operand 24 ec te hoa hd did Bhd ace dhe tt oo EE a E bedee wen hired enaed aes 7 Formal parameter Actual parameter 00 cece eee 7 Conditional Unconditional Call assas aeaee eunea eeaeee 7 General information 0 0c cece eect eee eee 9 General instructionS 222 60 isos tae yea oo ive beni vine epee 10 Function Blocks sce sic ties aa pas fate meh e ts Ad nana deka ee REUE Mckee As 10 Scaling and descaling within a control program 2 eee eee eee ee 11 General instructions 0 cece ect e eee eee ene 11 Single loop Controls 2 cece eect E eee eens 12 Multi loop controls 0 0 c cette eee eee ee 13 EFB Descriptions ii c vasa ia eae atte ee haa da aa ee 15 CC2_VAC Cascade controller for air conditi
11. The overflow of the most significant unit is allowed e g the entry T 25H15M is allowed Example t 14MS T 14 7S time 18M TIME 19 9H t 20 4D T 25H15M time 5D14H12M18S3 5MS Document window A window within an application window Several document windows can be opened simultaneously in one application window But only one document window at a time can be active Examples of document windows in Concept are sections the message window the Reference Data editor and the PLC configuration DX Zoom This is a feature that allows you to interface with a programming object to observe it s data values and alter them if necessary 87 Glossary E EFB see Elementary functions Function blocks Elementary functions Function blocks EFB A term for functions or function blocks with type definitions that are not formulated in one of the IEC languages for instance the DFB editor Concept DFB cannot be used to modify their bodies EFB types are programmed in C and are made available in compiled form via libraries EN ENO enable enable out If the value of EN is equal to 0 when the FFB is invoked the algorithms defined by the FFB will not be executed and all ouptupts remain with their old values In this case the value of ENO is automatically set to 0 If the value of EN is equal to 1 when the FFB is invoked the algorithms defined by the FFB will be executed After these algorithms have execu
12. a BCD switch at the rear of the module 96 22 Glossary 0 Operand An operand is a literal a variable a function call or an expression Operator An operator is a symbol for an arithmetic or boolean operation to be executed Output holding bits 0x references An output holding bit can be used to control real output data through an output unit of the control system or to define one or more discrete outputs in State RAM Note The x placed after the first digit of the reference type represents a five digit memory location in user data memory e g reference 000201 signifies an output or holding bit at address 201 of State RAM Output holding register 4x references An output holding register can be used to store numerical data binary or decimal in State RAM and or to send data from the CPU to an output unit in the control system Note The x placed after the first digit of the reference type represents a five digit memory location in user data memory e g reference 400201 signifies a 16 bit output holding register at address 201 of State RAM Output parameter output A parameter used to return the result s of the evaluation of an FFB P Peer processor The peer processor manipulates the token passes and the data flow between the Modbus Plus network and the PLC user logic PLC Programmable Logic Controller Program The top level program organization unit A program is downloaded into a single PLC a
13. a result of the boolean AND link of the state of the horizontal link at its left side with the state of the attached variable direct address A contact does not change the value of the attached variable direct address D Data transfer settings Settings that determine how information is transferred from your programming unit to a PLC 84 22 Glossary Data types ANY ANY ELEM ANY NUM ANY_REAL L REAL L ANY_INT DINT INT UDINT L UINT ANY_BIT BOOL BYTE L WORD TIME System data types IEC extension ANL_IN L ANL_OUT L Derived from ANY data types The overview shows the hierarchy of generic data types as used with inputs and outputs of functions and function blocks Generic data types are identified by the prefix ANY DCP drop A Distributed Control Processor D908 can be used to set a distributed network with a superior PLC When using a D908 with distributed PLC the primary PLC regards the distributed PLC as a head setup station The D908 and the distributed PLC are communicating via the system bus which results in high performance with minimal effect on scan time Data exchange between the D908 and the primary PLC is carried out via the distributed I O bus at 1 5 mega bits per second A primary PLC can support up to 32 D908 processors 22 85 Glossary DDE Dynamic Data Exchange The DDE interface is
14. conditions in the room lf an application requires tight control of temperature to an absolute value the CC3_VAC function block should not be used However for applications that do not require tight absolute control the PPI controller provides a simple stable and easy to use control algorithm The Pl controller setpoint can be maintained within minimum and maximum limits by using the P controller output limits YMAX1 and YMIN1 This facility can be used to prevent large swings in the inlet air temperature Manual Operation There are 3 possible modes of manual operation which are specified by setting the mutually exclusive NORM MAN_CTR and MAN_SEQ parameters NORM mode NORM 1 The output of the Pl controller output is set to zero The zero value is fed to the output sequences that are active in NORM mode As a result the actual values of Y1 and Y2 that are output to the control actuators will depend on the output sequence parameters In the case where the controller output limits YMIN2 and YMAX2 have been set to values that do not enclose zero the output will be set to the value of YMIN2 and YMAX2 that is closest to zero In other words Y YMAX2 if YMAX2 lt 0 AND YMIN2 lt 0 Y YMIN2 if YMAX2 gt 0 AND YMIN2 gt 0 Again the actual values of Y1 and Y2 that are output to the control actuators will depend on the output sequence parameters MAN_CTR mode MAN_CTR 1 The output of the PI controller is set equal to the user sp
15. control valve will result in more of the water circulating through the check valve and less through the outside air heat exchanger Conversely opening the control valve will result in more water circulating through the outside air heat exchanger Figure 5 Example Heat Recovery Exchangers EXHAUST E H RETURN AIR T S OUTSIDE AIR P INLET AIR H E yb CURVE PV nan SELECTION P X os SP Tmin MC_VAC Antifreeze SEQUENCE A MAX POSITIVE GAIN fm YEXT Y PV z PI SP ROOM TEMPERATURE SEQUENCE B NEGATIVE GAIN The example shows two control loops an inlet air controller and an anti freeze controller The anti freeze controller measures the water loop temperature and is used to guarantee a minimum temperature so as to prevent freezing of return air condensed water on the return air exchanger surfaces The setpoint is set to a suitable value above 8the freezing point of water Under normal conditions the PV will be greater than the SP the controller output will be zero and the MAX selection block will ensure that the inlet air controller controls the heat exchangers If however the water temperature decreases 00 43 MC_VAG below the minimum setpoint the anti freeze controller output will increase and
16. direction is commonly used is air mixing and is shown in Figure 4 In this application return air from a room is mixed with the outside air to supply the inlet air to the room In the winter the outside air is at a lower temperature and humidity than the return air The return air is therefore mixed with the outside air to provide free heating of the outside air In the summer the return air may have a lower temperature and humidity than the outside air In this case the return air is mixed with the outside air to provide free cooling The example shows the use of temperature and humidity sensors on the return air and outside air being used to determine the control direction of the controller The example also shows control of the mixing air damper It is then assumed that the outside air damper is connected mechanically or electro mechanically to the mixing air damper Figure 4 Example for Air Mixing EXHAUST RETURN AIR D T OUTSIDE AIR J INLET AIR a 6 J y4 CURVE m SELECTION MC_VAC xX H PV SEQUENCE A PI SP ROOM yh TEMPERATURE NEGATIVE GAIN 4 x SEQUENCE B In the winter if H_OUTSIDE lt H_RETURN sequence B is used In this case it can be seen that if the inlet air temperature is too low the PI controller output whose gain is 41 MC_VAG negative will be increasingly negative opening the mixin
17. error SP PV1 multiplied by the GAIN would trim the setpoint to the Pl controller resulting in a lowering of the inlet air temperature to offset the heat source in the room Because the inlet air dynamics are much faster than the room air dynamics a stable steady state condition will be reached under fluctuating room conditions using this cascaded approach A simple Pl controller using the room temperature as process variable would not achieve satisfactory control 00 21 CC2_VAC 3 3 because of the dead time between the adjustment of the inlet air temperature and a reaction in the room air temperature Please note however that while this PPI control algorithm will result in a stable room temperature there will be a small offset from the PPI controller setpoint i e PV1 will never equal SP The size of the offset will depend on the disturbance conditions in the room lf an application requires tight control of temperature to an absolute value the CC2_VAC function block should not be used However for applications that do not require tight absolute control the PPI controller provides a simple stable and easy to use control algorithm The Pl controller setpoint can be maintained within minimum and maximum limits by using the P controller output limits YMAX1 and YMIN1 This facility can be used to prevent large swings in the inlet air temperature Manual Operation There are 3 possible modes of manual operation which are
18. in the SFC editor function blocks in the FBD editor within a section graphically represented as a line Literals Literals are used to provide inputs of FFBs transition conditions etc directly with values These values cannot be overwritten by the program logic read only LL Refer to Ladder Logic 984 LL Local Derived data types Local Derived data types are only available in one single Concept project and its local DFBs and are deposited in the DFB directory below the project directory Local DFBs Local DFBs are only available in one single Concept project and are deposited in the DFB directory below the project directory Local link The local network link is the network that connects the local node with other nodes either directly or through a repeater Local Macros Local Macros are only available in one single Concept project and are deposited in the DFB directory below the project directory Local network node The local node is the one that is currently being configured Located Variable The variable is assigned an address in the PLC Located variables are used in the SFC and FBD editors in order to read signal states from the PLC and to turn them over to the PLC Additionally located variables can be exported and displayed via a DDE interface 22 95 Glossary Macro Macros are created by using the software Concept DFB Macros are used to duplicate often used sections and networks including their logi
19. line Mixed air damper activated SEQ_VAC sP_ _ _ vy Y t X 100 7 cy gt 15 MAN i P 415 4 a w 4 PI VAC ler 100 SP MAX l Y SEQ_VAC H vec YMAN_PC m Y X 100 po j YEXT 15 MAN a ry gt 415 NORM Module 5 gt A control OJ EF 100 MAN_CTR 7 THRS_VAC MAN_SEQ switching CMP_TI AE J Contra directi OUT i _ irection CMP_H1 CMP_T2 ii AE gt 0 A 1 RET AE lt 0 ft A0 MP_H2 GMP MX Mixed Air Damper OA Outside Air Damper OUT Outside Air Temperature Humidity PARA_MC gt Module parameters RET Return Air Temperature Humidity 00 35 MC_VAG 3 2 3 3 Please refer to the respective individual basic function block description for detailed information Setpoint The setpoint for the MC_VAC function block is fed to the Pl controller via the summer winter compensation block SW_VAC description see page 54 The Pl controller setpoint can be maintained within minimum and maximum limits by using the P controller output limits YMAX1 and YMIN1 This facility can be used to prevent large swings in the inlet air temperature as a result of unusual room temperature fluctuations or a badly adjusted P controller Control Direction The function block has 4 reference variables CMP T1 CMP_H1 CMP_T2 and CMP_H2 CMP_T1 is added to CMP_H1 and CMP_T2 is added to CMP_H2 The resulting additions are then compared with one another an
20. used for a dynamic data exchange between two programs that are using Windows With the DDE link between Concept and Concept Graphic Tool plant signals can be displayed as a Timing Diagram DDT see Derived Data Type Declaration Mechanism for specifying the definition of a language element A declaration normally involves attaching an identifier to a language element and allocating attributes such as data types and algorithms Definition file Concept EFB The definition file contains general descriptive information concerning the EFB and its formal parameters Derived data type Derived data types are data types that have been derived from Elementary data types and or other Derived data types Derived data types are defined in the Data Type editor of Concept There is a differentiation between Global data types and Local data types Derived Function Block DFB A derived function block represents the invocation of a derived function block type Details about the graphical form of the invocation can be found in the definition Function Block instance Contrary to invocations of EFB types invocations of DFB types are identified by double vertical lines to the left and right side of the rectangular block symbol The body of a derived function block type is designed in FBD language however only in the current version of the programming system At this time other IEC languages cannot be utilized for the definition of DFB types
21. 33000854 03 Concept Functionblocks for Heating Ventilation amp Air Condition HVAC Version 2 5 Block Library 840 USE 478 00 12 03 Data Illustrations Alterations Data and illustrations are not binding We reserve the right to alter products in line with our policy of continuous product development If you have any suggestions for improvements or amendments or have found errors in this publication please notify us using the form on one of the last pages of this publication Training Schneider Automation offers suitable further training on the system Hotline See addresses for the Technical Support Centers at the end of this publication Trademarks All terms used in this publication to denote Schneider Automation products are trademarks of Schneider Automation Allother terms used in this publication to denote products may be registered trademarks and or trademarks of the corresponding Corporations Microsoft and MS DOS are registered trademarks of Microsoft Corporation Windows is a brandname of Microsoft Corporation in the USA and other countries IBM is a registered trademark of International Business Machines Corporation Intel is a registered trademark of the Intel Corporation Copyright All rights are reserved No part of this document may be reproduced or transmitted in any form or by any means electronic or mechanical including copying processing or by online file transfer without permission in writing by
22. C3_VAC Table 2 PARA_CC3 Element Data Type Meaning SP_SPCV BOOL Setpoint setpoint command variable P controller YMAX1 REAL Upper limit manipulated variable YMIN1 REAL Lower limit manipulated variable GAIN1 REAL Controller gain PROP1 REAL Proportional value PREF1 REAL Proportional value reference PI Controller YMAX2 REAL Upper limit manipulated variable YMIN2 REAL Lower limit manipulated variable GAIN2 REAL Controller gain PROP2 REAL Proportional value PREF2 REAL Proportional value reference TI2 TIME Reset time 1 Sequence Xii REAL 1 Abcissa value Y1_1 REAL 1 Ordinate value X2_1 REAL 2 Abcissa value Y2_1 REAL 2 Ordinate value 2 Sequence X1_2 REAL 1 Abcissa value Y1_2 REAL 1 Ordinate value X2_2 REAL 2 Abcissa value Y2 2 REAL 2 Ordinate value 3 Sequence X1_3 REAL 1 Abcissa value Y1_3 REAL 1 Ordinate value X2_3 REAL 2 Abcissa value Y2 3 REAL 2 Ordinate value 00 27 CC3_VAC 3 1 Detailed description EFB structure A block diagram representation of the CC3_VAC complex function block is shown in Figure 1 It is made up of the following basic function blocks m SW_VAC Summer winter compensation see page 54 m PIVAC Basic PI controller for HVAC applications see page 45 m SEQ VAC Output Sequence scaling module see page 49 Please refer to the respective individual basic f
23. Note For the work with this software package the user must have acquired knowledge of closed loop control 00 About q OP y ly ZIN Example y quy Symbols used Note This symbol is used to draw your attention to important circumstances Caution This symbol indicates error sources which occur frequently Warning This symbol points out potential dangers to you which could result in financial damage personal injury or other serious consequences Expert This symbol is used if more detailed information is given which is intended exclusively for experts with special training Skipping this information does not affect comprehensibility of the document and does not restrict standard application of the product Tip This symbol draws your attention to explanations given in special tips which help you in your dealings with the product This symbol indicates an application example Proceed as follows The start of a sequence of applications the execution of which is necessary to obtain a specific product function is marked with this This symbol indicates manuals other sources dealing with the topic in greater detail 00 About Terms and abbreviations used The notation used for figures is in line with international practice as well as a type of representation allowed by SI Syst me International d Unit s Thousands are separated by a space and the decimal point is
24. Output variable 2 as a ERR REAL System Deviation 60 00 UC2_VAC Table 2 PARA_UC2 Element Data Type Meaning SP_SPCV BOOL Setpoint setpoint command variable PI Controller YMAX REAL Upper limit manipulated variable YMIN REAL Lower limit manipulated variable GAIN REAL Controller gain PROP REAL Proportional value PREF REAL Proportional value reference Tl TIME Reset time 1 Sequence X1_1 REAL 1 Abcissa value Y1_1 REAL 1 Ordinate value X2_1 REAL 2 Abcissa value Y2_1 REAL 2 Ordinate value 2 Sequence X1_2 REAL 1 Abcissa value Y1_2 REAL 1 Ordinate value X2_2 REAL 2 Abcissa value Y2 2 REAL 2 Ordinate value 00 61 UC2_VAC 3 1 Detailed description EFB Structure A block diagram representation of the UC2_VAC complex function block is shown in Figure 1 It is made up of the following basic function blocks m SW_VAC Summer winter compensation see page 54 m PIVAC Basic PI controller for HVAC applications see page 45 m SEQ VAC Output Sequence scaling module see page 49 Please refer to the respective individual basic function block description for detailed information Figure 1 Controller structure SW_VAC SP p YMAN1_PC SEQ_VAC IM E ee YA PIVAC SP Y1_PC
25. REAL Proportional value reference PI Controller YMAX2 REAL Upper limit manipulated variable YMIN2 REAL Lower limit manipulated variable GAIN2 REAL Controller gain PROP2 REAL Proportional value PREF2 REAL Proportional value reference TI2 TIME Reset time 1 Sequence Xii REAL 1 Abcissa value Y1_1 REAL 1 Ordinate value X2_1 REAL 2 Abcissa value Y2_1 REAL 2 Ordinate value 2 Sequence X1_2 REAL 1 Abcissa value Y1_2 REAL 1 Ordinate value X2_2 REAL 2 Abcissa value Y2 2 REAL 2 Ordinate value 00 19 CC2_VAC 3 1 Detailed description EFB structure A block diagram representation of the CC2_VAC complex function block is shown in Figure 1 It is made up of the following basic function blocks m SW_VAC Summer winter compensation see page 54 m PIVAC Basic PI controller for HVAC applications see page 45 m SEQ VAC Output Sequence scaling module see page 49 Please refer to the respective individual basic function block description for detailed information Figure 1 Controller structure SW_VAC SP _ l YMAN1_PC gt A CV e __ Y1 Y1_PC PI_VAC sas PI_VAC PV1 YMAN2_PC Pv2 Y2 YMAN_PC gt K gt Y2 PC NORM Module control MAN_CTR MAN_SEQ ae PARA_CC2 _______ Module parameters
26. ROP mode is activated In this mode a change in the PV by an amount PROP will result in a change of the controller output by an amount PREF In other words for a P only controller the output is calculated as Y PREF SP PV PROP In the case where an actuator is connected directly to the output of the controller a PREF of 100 can be set to indicate 100 output A negative value of PROP may be specified to reverse the action of the controller However PREF must always be specified as positive m If GAIN 0 and PROP 0 the proportional value of the controller is effectively switched off By specifying an integral time using the TI input the controller will act as an l only controller In the event that the integral time TI is set to zero there will be no PI action at all and only the BIAS value will be forwarded to the controller output In this case the operating modes MAN HALT and DHALT will still be active Manual Operation There are 3 possible modes of manual operation which are specified by setting the mutually exclusive MAN HALT and DHALT parameters MAN mode MAN 1 The value specified at YMAN is written to the controller loop output Y This is effective in both P and PI modes The contribution is continually tracked to allow bump less switching of the controller back to automatic mode The output limits and anti reset windup are therefore still active in MAN mode 00 47 PI_VAC HALT mod
27. VAC blocks It is important to note that the smaller value of Y1 and Y2 is always equated to 0 and the greater value to 100 In other words the percentage value is related to the size of the output variable Y irrespective of its direction Y1 lt Y2 gt 0 100 Y1 Y2 Y1 gt Y2 gt 0 100 Y2 Y1 For more information on the operation of the SEQ_VAC block please refer to the respective description see page 49 64 00 UC3_VAC UC3_VAC Universal PI controller for air conditioning with 3 outputs Brief description The UC3_VAC complex function block is a general Pl controller designed for air conditioning applications It can be used for temperature control humidity control air mixing control or other general functions It consists of a PI controller summer winter setpoint compensation and 3 output sequences The EFB provides the following Winter summer setpoint compensation as per DIN 1946 part 2 Full four quadrant operation of the output sequence scaling The display of output variables as percentages Upper and lower limits on outputs Presetting the controllers gains in the form of GAIN or PROP with the possibility of using negative values for switching the control direction Operation with Anti Windup Reset AWR Manual adjustment of either the Pl controller total output or the individual sequence outputs Y1 and Y2 using percentages When the controller output is manually adju
28. While the CC2_VAC function block can be used for both temperature or humidity control the remainder of this description refers to temperature control only 20 00 CC2_VAC 3 2 Basic Operation The setpoint for the CC2_VAC function block is fed to the P controller via the summer winter compensation block SW_VAC description see page 54 The output of the SW_VAC block is fed not only to the setpoint of the room P controller but also to its BIAS input In this way the P controller setpoint is added to the P controller output which is equal to the P controller error amplified by the controller gain and the result is fed as setpoint to the inlet air Pl controller This is shown in Figure 2 Figure 2 Diagram of setpoint formation PV1 Room temperature Room air P contribution adjustable from 0 to the point of instability Inlet air PI Y O SP Direct setpoint or Command variable PV2 Inlet air temperature In order to understand the operation of this PPI controller consider the case of a room with no temperature gains or losses In this case the room temperature PV1 would be equal to the PPI controller setpoint and the inlet air temperature PV2 would be equal to the room temperature PV1 If we now consider the case of a heat source in the room the room air temperature PV1 will rise to a value greater than the setpoint As a result the output of the P controller equal to controller
29. Y and Y_PC The percentage values specified for the manual control of outputs YH_PC and YMAN_PC refer to the specified range of the appropriate output For example the variable YH_PC sets the total output of the PI_VAC basic function block The range of this output is specified by the parameters YMIN 0 and YMAX 100 The variable YMAN_PC sets the output of the SEQ_VAC block the range of which is specified by the corresponding ordinate vales Y1 Y2 where Y1 and Y2 refer to the SEQ_VAC ordinates It is important to note that the smaller value of Y1 and Y2 is always equated to 0 and the greater value to 100 In other words the percentage value is related to the size of the output variable Y irrespective of its direction Y1 lt Y2 gt 0 100 Y1 Y2 Y1 gt Y2 gt 0 100 Y2 Y1 For more information on the operation of the SEQ_VAC block please refer to the respective description see page 49 Example Applications You will find two examples for using the MC_VAC block m Air Mixing m Heat Recovery Exchangers Note In both of the examples the user must carefully select all control actuators in order to provide failsafe operation and prevent freezing of water coils Hardwired antifreeze controls should also be used to override the PLC controls and if necessary shutdown the make up air handling unit to protect the coils 40 00 MC_VAC Example Air Mixing An example where switching of control
30. _0 or 16 E0 decimal 224 Binary links Links between outputs and inputs of FFBs in data type BOOL Bit string A data element consisting of one or more bits BOOL BOOL represents the data type boolean The length of the data elements is 1 bit stored in memory in 1 byte The value range for variables of this data type is 0 FALSE and 1 TRUE Bridge A bridge is a device that connects networks It enables communication between nodes on the two networks Each network has its own token rotation sequence the token is not passed along through bridges 22 83 Glossary BYTE BYTE represents the data type bit string 8 It is entered as base 2 literal base 8 literal or base 16 literal The length of the data elements is 8 bits This data type cannot be assigned a numeric value range c Coil A coil is an LDelement that transfers the state of the horizontal link at its left side without any change to the horizontal link at its right side Through this the state is stored in the attached variable direct address Compact format 4 1 The first digit of the reference is separated from the address that follows by a colon and no leading zeros are entered in the address Constants Constants are unlocated variables that are assigned a value that cannot be changed by the program logic read only Contact A contact is an LDelement that transfers a state to the horizontal link at its right side This state is
31. ating mode switchover P 1 PI or GAIN PROP DHALT MAN Limitation HIGH DHALT MANUAL HALT LOW gt QMIN 48 00 SEQ_VAC SEQ_VAC Scaling Sequence Block for Air Conditioning Brief description SEQ_VAC is a basic function block that can be used to scale real input variables to real output variables using a linear relationship The block can be used to scale both process variable inputs as well as controller outputs The scaling is performed in the form of cartesian coordinates The input variable range is specified as X1 X2 The output variable range is specified as Y1 Y2 The EFB provides the following Full four quadrant operation allowing the creation of both positive negative forward and reverse acting sequences Limitation of the outputs Y1 _Y2 when the input range X1 X2 is exceeded When this happens the variables QMIN and QMAX are set A manual operation mode to allow the presetting of the output in percentage form Display of the output in both REAL and percentage form Additional parameters EN and ENO may be configured You will find this EFB in the HVAC library 00 49 SEQ_VAC 2 1 2 2 Representation Symbol SEQ_VAC REAL x y REAL REAL x1 Y_Pc REAL REAL Y1 REAL x2 REAL y2 BOOL MAN QMAX BOOL REAL YMAN_PC QMIN BOOL Parameter Specifi
32. c variables and variable declaration Local and global macros are available Macros have the following characteristics Macros can only be created in the FBD programming language Macros contain only one single section Macros may contain any complex section With regard to the program an instantiated macro i e a macro inserted in a section does not differ from a conventionally created section DFBs can be invoked in a macro Macro intrinsic variables can be declared for the macro Macro intrinsic data structures can be used Automatic acceptance of variables declared in the macro Initial values for the macro variables are possible The multiple instantiation of a macro in the total program with different variables is possible m The section name the names of variables and the data structure name can have the character as a swap marking MMI Man Machine Interface Multi element variables Variables that are assigned a Derived data type that is defined with STRUCT or ARRAY There is a differentiation between array variables and structured variables N Network A network is the interconnection of units along a shared data path that are communicating with each other via a common protocol Network Node A node is a unit with an address 1 64 on the Modbus Plus network Node address The node address is used to uniquely identify a network node in the routing path The address is set directly on the node e g with
33. cation of an FFB it transfers the corresponding argument Input registers 3x references An input register contains information from an external source which is representing a 16 bit number A 3x register can also contain 16 sequential input bits that were read into the register in binary or BCD binary coded decimal format Note The x placed after the first digit of the reference type represents a five digit memory location in user data memory e g reference 300201 signifies a 16 bit input register at address 201 of state RAM Instance see Function Block instance Instance Name An identifier associated with a specific function block instance The name of the instance is used to uniquely identify a function block in a program organization unit This instance name is automatically created but it can be edited The instance name must be unique throughout the program organization unit there is no distinction between upper and or lower case If the name entered already exists you will be warned and another name must be chosen The instance name must comply with the IEC naming conventions or an error message will appear The automatically created instance name will always have the structure FBI_n_m FBI function block instance n number of section consecutive number m number of the FFB object in the section consecutive number 92 22 Glossary Instantiation The creation of an instance Instruction IL Ins
34. cations Parameter Data Type Meaning X REAL Input variable x1 REAL 1 Abcissa value 1 Value pair Y1 REAL 1 Ordinate value 1 Value pair X2 REAL 1 Abcissa value 2 Value pair Y2 REAL 1 Ordinate value 2 Value pair MAN BOOL MANUAL mode YMAN_PC REAL Manual control value 0 100 Y REAL Output variable control value Y_PC REAL Output variable as a QMAX BOOL Upper limit of signalling device reached AMIN BOOL Lower limit of signalling device reached 50 00 SEQ_VAC 3 1 3 2 Detailed description Basic Operation The SEQ_VAC module is processed in each active cycle Examples of the use of SEQ_VAC can be find in chapter 2 General Information Figure 2 Parameter Specifications The input variable to be scaled is denoted as X The range over which it is to be scaled is specified by X1 and X2 X1 must be less than X2 The corresponding output range is specified by the parameters Y1 and Y2 If the input range X1 lt X lt X2 is exceeded the output variable is clamped to the limits represented by the values Y1 and Y2 such that Y x gt x2 Y2 and Y xex1 Y1 If the input range is exceeded and clamping is activated this is indicated by the setting of the variables QMAX and QMIN An increasing sequence is specified by setting Y1 lt Y2 A decreasing reverse acting sequence is specified by specifying Y1 gt Y2 The percentage value of the scaling result is output at Y_PC It is importan
35. d the result of the comparison is fed to the THRS_VAC block to provide switching with a built in hysteresis of 1 0 The output of the THRS_VAC block is used to reverse the action of the output sequences The user is free to choose what inputs are connected to the reference variables In general though temperature comparisons should use CMP_T1 and CMP_T2 while humidity comparisons should use CMP_H1 and CMP_H2 If temperature comparison only is required the variables CMP_H1 and CMP_H2 can be set to zero The comparison inputs can be used to compare the heat content of 2 air streams The heat content of air can be calculated as follows Q Qa Qsw Qw Where Qa sensible heat content of air kJ Qsw sensible heat content of water vapor kJ Qw latent heat content of water vapor kJ Therefore Q m Ca Ta m xX Cw Ta m xX hw Where m mass of air kg Ca specific heat capacity of air 1 006 kJ kg K Ta temperature of air deg C x absolute humidity g kg Cw specific heat capacity of water vapour 1 92 kJ kg K hw specific enthalpy of water vapour 2500 kJ kg 2 5 kJ g 36 00 MC_VAC 3 4 Bearing in mind that Ca is approximately equal to one and that hw is much greater than Cw Ta the equation can be simplified to Q m Ta m hw x Therefore the enthalpy H of the air can be calculated as H Q m Ta hw X Ta 2 5x Therefore by scaling the air temperature in degrees Celsius a
36. des the data types BOOL BYTE DINT INT REAL UDINT UINT TIME and WORD ANY_INT In this version ANY_INT includes the data types DINT INT UDINT and UINT ANY_NUM In this version ANY_NUM includes the data types DINT INT REAL UDINT and UINT 22 81 Glossary ANY_REAL In this version ANY_REAL includes the data type REAL Application Window The window containing the workspace the menu bar and the tool bar for the application program The name of the application program appears in the title bar One application window may contain several document windows In Concept the application window corresponds to a project Argument Synonymous with actual parameter Array variables Variables that are assigned a defined derived data type using the keyword ARRAY field An field is a collection of data elements of the same data type ASCII mode American Standard Code for Information Interchange The ASCII mode is used for communication with different host devices ASCII works with 7 data bits Atrium The PC based controller which is based on a 386 EX microprocessor is mounted on a standard AT Platine and can be used inside a Host Computers on an ISA bus slot The module has a motherboard SA85 driver needed with 2 sockets for PC104 daughter boards One of this PC104 Daughter Board is used as CPU and the other is used for Interbus S controlling Backup file Concept EFB The backup fi
37. e HALT 1 In HALT mode the controller output is frozen at its current value The contribution is tracked to allow bump less switching back to automatic mode DHALT mode DHALT 1 This mode is used to prevent step changes to the controller output when the setpoint is changed When the setpoint is changed the controller contribution is adjusted so that the controller output does not change on the next controller cycle The controller will subsequently integrate the output in a ramp like fashion until the PV reaches the new SP 3 3 Output Parameters The controller output is set at Y The range of the output is defined by the parameters YMIN and YMAX When these limits are reached the parameters QMIN and QMAX are set In the event that an output limit is reached anti reset windup is activated This prevents the I contribution from continually integrating and guarantees that when the controller inputs create a change of direction of the output the output Y will be immediately released from the upper or lower limit Figure 6 Controller structure TI 0 1 XI I 1 a YMAX YMIN i P 07 AWR T y m QMAX i A XI I 1 GAIN aan PROP PREF A Tl SP 3 Xd GAIN 0 amp CV PROP 0 GAIN 0 amp 5 PROP 0 BIAS YMAN Priority controller operating mode Oper
38. e If the EN input is not parameterized it must be hidden or the FFB will never be executed 00 Parameter assignment 00 General information 9 In this chapter you will find general information about using EFB library air conditioning HVAC modules Note For the work with this software package the user must have acquired knowledge of closed loop control 00 General information 2 1 General instructions The HVAC EFB library puts at your disposal an extensive range of function blocks for the implementation of air conditioning systems using the Concept programming language 2 2 Function blocks 11 function blocks are available split up as follows m 6 basic function blocks Basic Group see Table 1 5 complex function blocks Complex Group see Table 2 Basic Function Blocks The basic function blocks implement low level functions that are required for solving basic airconditioning problems Table 1 Basic Functions Blocks Function Block Description PI_VAC PI Controller for Air Conditioning SEQ_VAC Scaling Sequence Block for Air Conditioning SW_VAC Summer Winter Setpoint Compensation for Air Conditioning THRS_VAC Threshold Switch with Hysteresis for Air Conditioning VQ_VAC Measured Value Deadband Block WASH_VAC Basic Washer Block for Air Conitioning General information 2 3 2 3 1 Complex Function Blocks The complex func
39. e command variable CV The compensation curves are shown in Figure 1 Figure 1 Summer Winter compensation curve SPComp Degrees C 26 02 See SS Reo Sa ee a ea CV Degrees C 1 ao 10 0 0 0 22 0 32 0 The SP_SPCV input can be used to switch the block s mode of operation In Setpoint mode SP_SPCV 0 no compensation is performed and SPRT SP In Setpoint with command variable mode SP_SPCV 1 compensation is performed and SPRT SP SPComp as shown in Figure 2 Figure 2 Module structure SP SPRT Compensation curve SP_SPCV Under normal circumstances when operating in compensation mode SP is set to zero and SPRT SPComp However the user may choose to input a value for SP This will 55 SW_VAC 3 2 have the effect of moving the summer winter compensation curve shown in Figure 1 vertically up or down Parameter Specifications The command variable is specified in degrees Celsius The setpoint SP is a real value and should be scaled as appropriate The output of the block SPRT is scaled as a real value 56 00 THRS_VAC 2 1 2 2 THRS_VAC Threshold Switch with Hysteresis for Air Conditioning Brief description THRS_VAC is a basic function block that is used to detect a threshold on a REAL variable with a built in hysteresis The EFB provides the following The setting of an on and off thresh
40. e configured You will find this EFB in the HVAC library Representation Symbol WASH_VAC REAL SP_T SP_TWK REAL REAL SP_RH Parameter Specifications Parameter Data Type Meaning SP_T REAL Setpoint temperature at target location room temperature SP_RH REAL nominal value rel humidity at target location room humidity SP_TW REAL Setpoint washer outlet temperature 74 00 WASH_VAC 3 1 Detailed description Basic Operation The principle of operation of the WASH_VAC basic function block relies on the fact that the dewpoint temperature of air is equal to the dry bulb temperature when the air is fully saturated i e its relative humidity is equal to 100 The purpose of the WASH_VAC basic function block is to calculate the dewpoint temperature setpoint SP_TW based on a specified room temperature setpoint SP_T and relative humidity setpoint SP_RH Fora washer application by controlling the washer outlet temperature to SP_TW one guarantees that when the air is reheated to the room temperature setpoint SP_T the room relative humidity value will equal SP_RH This can be done because reheating the air does not change the air s absolute humidity but only its dry bulb temperature and therefore its relative humidity It therefore follows that if one can guarantee that the washer outlet air has a relative humidity of 100 the dewpoint temperature can be measured and control
41. e inlet air to a room It consists of a P only outer loop which uses the room temperature humidity as process variable and an inner PI loop that controls the temperature humidity of the inlet air supplying the room The EFB has a fixed structure where the setpoint of the P controller is fed forward and added to the P controller output to form the setpoint of the Pl controller The output of the Pl controller has 2 output sequences Y1 and Y2 The EFB provides the following Winter summer setpoint compensation as per DIN 1946 pert 2 Full four quadrant operation of the output sequence scaling The display of output variables as percentages Upper and lower limits on outputs Presetting the controllers gains in the form of GAIN or PROP with the possibility of using negative values for switching the control direction Operation with Anti Windup Reset AWR Manual adjustment of either the Pl controller output or the individual sequence outputs Y1 and Y2 using percentages When the controller output is manually adjusted the EFB tracks the contribution in order to provide bump less switching back to automatic mode m The display of the P and PI controller errors SP PV SES Note Additional parameters EN and ENO should not be configured You will find this EFB in the HVAC library 00 17 CC2_VAC 2 Representation 2 1 Symbol CC2_VAC REAL
42. ecified parameter YMAN_PC Again the output sequences are active in this mode and therefore the actual values of Y1 Y2 and Y3 that are output to the control actuators will depend on the output sequence parameters MAN_SEQ mode MAN_SEQ 1 The outputs Y1 Y2 and Y3 are set to the values specified by the parameters YMAN1_PC YMAN2_PC and YMAN3_PC i e Y1_PC YMAN1_PC Y2_PC YMAN2_PC and Y3_PC YMAN3_PC In MAN_CTR mode the contribution of the Pl controller is tracked so that a bumpless transfer back to automatic mode may be carried out In NORM and MAN SEQ modes the contribution is set to zero 30 00 CC3_VAC 3 4 Output Parameters The CC3_VAC outputs Y1 Y2 and Y3 are available in real or percentage form Y1 Y2 Y3 Y1_PC Y2_PC and Y3_PC The percentage values specified for the manual control of outputs YMAN_PC YMAN1_PC YMAN2_PC and YMAN3_PC refer to the specified range of the appropriate output For example the variable YMAN_PC sets the total output of the PI_VAC basic function block The range of this output is specified by the parameters YMIN 0 and YMAX 100 The variables YMAN1_PC YMAN2_PC and YMAN3_PC set the outputs of the two SEQ_VAC blocks the ranges of which are specified by their corresponding ordinate vales Y1 Y2 where Y1 and Y2 refer to the SEQ_VAC ordinates not the actual outputs Y1 Y2 and Y3 of the two SEQ_VAC blocks It is important to note that the smaller value of Y1 and Y2 i
43. ed information Figure 1 Controller structure SW VAC YMAN1_PC SEQ_VAC SP Y1 CV m Y1_PC YMAN2_PC PI VAC SEQ_VAC SP Bee PV gt Ha k H Y2_PC YMAN_PC YMAN3_PC EQ VAC 8 NORM al Module ri control Y3 P MAN_CTR gt H Y3_PC MAN_SEQ _ PARA_UC3S a Module parameters 68 00 UC3_VAC 3 2 3 3 Basic Operation The setpoint for the UC3_VAC function block is fed to the Pl controller via the summer winter setpoint compensation block SW_VAC description see page 54 The output of the SW VAC block is fed to the setpoint input of the PI controller The Pl controller output is fed to 3 sequence output blocks SEQ_VAC The Pl controller output can be maintained within minimum and maximum limits by using the Pl controller output limits YMAX1 and YMIN1 Manual operation There are 3 possible modes of manual operation which are specified by setting the mutually exclusive NORM MAN_CTR and MAN_SEQ parameters NORM mode NORM 1 The output of the Pl controller output is set to zero The zero value is fed to the output sequences that are active in NORM mode As a result the actual values of Y1 Y2 and Y3 that are output to the control actuators will depend on the output sequence parameters In the case where the controller output limit
44. ed by a rectangular block symbol The name of the function block type is centered on top inside the rectangle The name of the function block instance is also on top but outside the rectangle It is automatically 22 89 Glossary generated when building an instance but it can be modified by the user if necessary Inputs are shown to the left outputs to the right of the block The names of the formal input output parameters are shown inside the rectangle at the corresponding input output points Above description of the graphical presentation applies generally to function calls and to DFB calls as well Any differences are described in the respective definitions Function block type A language element that consists of 1 the definition of a data structure subdivided into input output and internal variables 2 a set of operations processed with the elements of the data structure whenever an instance of the function block type is invoked This set of operations can either be formulated in one of the IEC languages DFB type or in C EFB type A function block type can be instantiated multiple times Function number The function number is used to uniquely identify a function in a program or DFB The function number cannot be edited it is automatically assigned The function number always has the structure n m n number of section consecutive number m number of the FFB object in the section consecutive number
45. g air damper in order to mix a greater quantity of warmer air with the colder outside air thereby increasing the inlet air temperature Conversely if the inlet air temperature is too warm the PI controller output will be increasingly more positive resulting in a closing of the mixing air damper in order to mix a smaller quantity of the warmer return air with the cooler outside air thereby decreasing the inlet air temperature In the summer if H_OUTSIDE gt H_RETURN sequence A is used In this case it can be seen that if the inlet air temperature is too low the PI controller output whose gain is negative will be increasingly negative closing the mixing air damper in order to mix a smaller quantity of colder return air with the warmer outside air thereby increasing the inlet air temperature Conversely if the inlet air temperature is too warm the PI controller output will be increasingly more positive resulting in the opening of the mixing air damper in order to mix a greater quantity of cooler return air with the warmer outside air thereby decreasing the inlet air temperature 42 00 MC_VAC Example Heat Recovery Exchangers Another example of heat recovery exchangers is shown in Figure 5 In this example a closed water loop between two heat exchangers is used to transfer heat between the return air and incoming outside air A re circulation pump is used in combination with a check valve and control valve Closing the
46. g of inputs can be handled using standard Concept libraries or the HVAC library SEQ_VAC EFB can be used 00 11 General information 2 3 2 The complex EFB s include the controller plus one or more freely parameterizable output sequence blocks The behavior of a complex EFB can be determined by examining the basic EFB s from which it is built The complex EFB s are described in this document by referring to their constituent basic EFB s The combination of the controller with the output sequencing has been done to simplify the parameterization of the EFB as all the output sequence parameters can be assigned at the same time as the controller parameters Furthermore the links from the controller output to the sequenced outputs are automatically created with a fixed structure Single loop controls In the case of simple single loop controls the purpose of the output sequencing is simply to match the controller output to the process actuators For controllers operating in simple P mode the controller output will equal zero when the setpoint is equal to the process variable In this case the output sequencing must be able to handle negative controller outputs and convert them into signals for the actuators By assigning the appropriate values to the output sequences it is possible to design a P controller with a 50 output when the process variable is equal to the setpoint The advantage of such an approach is that o
47. hat are assigned a Derived data type that is defined with STRUCT structure A structure is a collection of data elements generally with different data types Elementary data types and or Derived data types 22 101 Glossary Source code file Concept EFB The source code file is an ordinary C source file After executing the menu command Library Generate files this file will contain an EFB code frame where a specific code for the selected EFB must be entered by invoking the menu command Objects gt Source auf SY MAX In Quantum controllers Concept includes the provision to I O Map SY MAX I O modules for RIO control by the Quantum PLC The SY MAX remote rack has a remote I O adapter in slot 1 that communicates via a Modicon S908 R I O system The SY MAX I O modules are listed for your selection and inclusion in the I O map of the Concept configuration System data types In the current version system data types include the data types ANL_IN and ANL_OUT T Template file Concept EFB The template file is an ASCII file containing layout information for the Concept FBD editor and parameters for generating code Temporary storage Temporary storage is temporary memory for cut or copied objects These objects can be inserted into sections Each time something new is cut or copied the old content in temporary storage is overwritten TIME TIME represents the data type duration It is entered as a duration li
48. he Pl controller output is fed through the Max Min block to the output sequence In Auxiliary mode the value passed through to the output sequence depends on the result of the comparison between the controller output and the value of YEXT which is set by the higher level controller Therefore in order to operate in true NORM mode both the Auxiliary controller and the higher level controller must be set to NORM The actual value that is output to the control actuator depends on the output sequence parameters MAN_CTR mode MAN_CTR 1 The output of the PI controller is set equal to the user specified parameter YMAN_PC However the YEXT value coming from the higher level controller may override the YMAN_PC value Again the output sequence is active in this mode and therefore the actual value of Y that is output to the control actuator will depend on the output sequence parameters and the control direction 00 39 MC_VAG 3 7 3 8 MAN_SEQ mode MAN_SEQ 1 The sequence output Y is set to the value specified by the parameter YMAN_PC i e Y_PC YMAN_PC When in MAN_SEQ mode switching the control direction has no effect on the output In MAN_CTR mode the contribution of the Pl controller is tracked so that a bump less transfer back to automatic mode may be carried out In NORM and MAN SEQ modes the contribution is set to zero Output Parameters The MC_VAC output Y is available in real or percentage form
49. he case where THRS_ ON is not equal to THRS_OFF when the variable X lies between the 2 thresholds the output YP remains in its current state until the opposite threshold is reached In this way a hysteresis function is provided see Figure 1 When THRS_ON THRS_ OFF the block acts as a comparator switch The THRS_VAC function block is processed in each cycle During the first cycle YP 0 and YN 1 The THRS_VAC block may be used as a switch in many applications such as summer winter compensation day night temperature drops anti freeze device etc 58 00 UC2_VAC UC2_VAC Universal PI controller for air conditioning with 2 outputs Brief description The UC2_VAC complex function block is a general Pl controller designed for air conditioning applications It can be used for temperature control humidity control air mixing control or other general functions It consists of a PI controller summer winter setpoint compensation and 2 output sequences The EFB provides the following Winter summer setpoint compensation as per DIN 1946 part 2 Full four quadrant operation of the output sequence scaling The display of output variables as percentages Upper and lower limits on outputs Presetting the controllers gains in the form of GAIN or PROP with the possibility of using negative values for switching the control direction Operation with Anti Windup Reset AWR Manual adjustment of either the Pl contr
50. igure 3 Sequence 4 1 Quadrant Y A X2 Y2 plie ta bye tye Sy Peete te ne Module inputs outputs 80 0 X1 6400 0 Y1 20 0 X2 32000 0 Y2 80 0 6400 0 0 X Analog value LZ standard signal 32000 0 20 0 X1 Y1 00 53 SW_VAC 2 1 2 2 SW_VAC Summer Winter Setpoint Compensation for Air Conditioning Brief description SW_VAC is a basic function block that provides summer winter compensation of a temperature setpoint based on the outside air temperature command variable CV The EFB provides the following Summer winter setpoint compensation with summer compensation following the DIN 1946 Part 2 standard Switchable operating modes offering the choice of compensation or no compensation Additional parameters EN and ENO may be configured You will find this EFB in the HVAC library Representation Symbol SW_VAC REAL SP SPRT REAL REAL cv BOOL SP_SPCV Parameter Specifications Parameter Data Type Meaning SP REAL Setpoint CV REAL Command variable as a rule the outside air temperature SP_SPCV BOOL Setpoint setpoint command variable SPRT REAL Setpoint room temperature 54 00 SW_VAC Detailed description Basic Operation The SW_VAC function block is processed in each cycle The function block is used to adjust the room or inlet air temperature setpoint SPRT based on the outside air temperatur
51. ing negative values for switching the control direction Bump less switching between GAIN and PROP operation in the case of PI control Operation with Anti Windup Reset AWR Manual operation mode with tracking of the contribution in order to provide bump less switching back to automatic mode HALT operating mode for freezing the controller output at its current value with tracking of the contribution DYNAMIC HALT operating mode that prevents step changes in the controller output when the setpoint is changed m Upper and lower limits on controller output with indication when limits are reached using the QMAX and QMIN outputs m The display of the PI controller error SP PV Note Additional parameters EN and ENO should not be configured You will find this EFB in the HVAC library 00 45 PI_VAC 2 1 2 2 Representation Symbol PI_VAC BOOL MAN BOOL HALT BOOL DHALT REAL SP yt REAL REAL pv ERR REAL REAL BIAS omax BOOL REAL YMAN OMIN BOOL REAL YMAx REAL YMIN REAL GAIN REAL PROP REAL PREF TIME TI Parameter Specifications Parameter Data Type Meaning MAN BOOL MANUAL mode HALT BOOL HALT mode DHALT BOOL Dyn HALT for next scanning step SP REAL Setpoint PV REAL Actual value BIAS REAL DEVIATION deviation compensation YMAN REAL Manual manipula
52. ir PI Y O SP Direct setpoint or Command variable PV2 Inlet air temperature In order to understand the operation of this PPI controller consider the case of a room with no temperature gains or losses In this case the room temperature PV1 would be equal to the PPI controller setpoint and the inlet air temperature PV2 would be equal to the room temperature PV1 If we now consider the case of a heat source in the room the room air temperature PV1 will rise to a value greater than the setpoint As a result the output of the P controller equal to controller error SP PV1 multiplied by the GAIN would trim the setpoint to the Pl controller resulting in a lowering of the inlet air temperature to offset the heat source in the room Because the inlet air dynamics are much faster than the room air dynamics a stable steady state condition will be reached under fluctuating room conditions using this cascaded approach A simple Pl controller using the room temperature as process variable would not achieve satisfactory control 00 29 CC3_VAC 3 3 because of the dead time between the adjustment of the inlet air temperature and a reaction in the room air temperature Please note however that while this PPI control algorithm will result in a stable room temperature there will be a small offset from the PPI controller setpoint i e PV1 will never equal SP The size of the offset will depend on the disturbance
53. le is a copy of the last source code file The name of this backup file is backup c assuming that there are never more than 100 copies of your source code file The name of the first backup file is backup00 c If the definition file has been modified without causing any interface change in the EFB it is not necessary to create a backup file by editing your source code file Objects gt Source If a backup file is generated you can name it Source file 82 22 Glossary Base 2 literals Base 2 literals are used to specify integer values in the binary system The base is identified by the prefix 2 The values cannot have a sign Individual underscore symbols _ between the numbers have no significance Example 2 1111_1111 or 2 11111111 255 decimal 2 1110_0000 or 2 11100000 224 decimal Base 8 literals Base 8 literals are used to specify integer values in the octal system The base is identified using the prefix 8 The values cannot have a sign Individual underscore symbols _ between the numbers have no significance Example 8 3_77 or 8 377 decimal 255 8 34_0 or 8 340 decimal 224 Base 16 literals Base 16 literals are used to specify integer values in the hexadecimal system The base is identified using the prefix 16 The values cannot have a sign Individual underscore symbols _ between the numbers have no significance Example 16 F_F or 16 FF decimal 255 16 E
54. led using a simple dry bulb temperature sensor rather than a more expensive humidity sensor An example is shown on the figure H X Diagram Figure 1 For a room temperature of 22 degrees Celsius and a relative humidity of 65 the WASH_VAC function block will calculate the dewpoint setpoint as 15 2 degrees Celsius By controlling the washer outlet temperature to 15 2 degrees Celsius and subsequently reheating the air to 22 degrees Celsius the room relative humidity will equal 65 00 75 WASH_VAC Figure 1 h x diagram with clarification of the method of operation of the WASH_VAC Temperature 99 C T Room e g 22 deg C T WA _ 15 2 deg C l R H e g 65 R H 100 Dew point characteristic curve quadratically approached Reheating Heat content h KJ Kg oe E 3 2 Parameters Xap XTP Absolute humidity X g Kg Xap 0 65 XTp The air temperature dry bulb temperature setpoint is specified by the variable SP_T in degrees Celsius The relative humidity is specified by the variable SP_RH as a value The washer outlet temperature setpoint is output in degrees Celsius at the location specified at SP_TW 76 00 WASH_VAC Example An example application consisting of a preheat coil cooling coil washer and reheat coil is shown in the Figure 2 The setpoint calculated by WASH_VAC is fed to a lower level PI controller whose PV is connected to the washer tem
55. m 0 to 2 exp 16 1 Unlocated Variable The variable is maintained and stored by the system The assigned address in the PLC is not published because the variable is addressed by its symbolic name V Variables Variables are used for data exchange within sections between several sections and between the program and the PLC If a variable is assigned a direct address reference it is called a located variable If a variable is not assigned a direct address it is called an unlocated variable If the variable is assigned a Derived data type it is called a multi element variable In addition there are constants and literals Ww Warning If a critical state is detected while an FFBs or step is processing e g critical input values or time limit was exceeded a warning occurs that can be viewed using the menu command Online gt Online events In FFBs the ENO output remains at 1 WORD WORD represents the data type bit string 16 It is entered as base 2 literal base 8 literal or base 16 literal The length of the data elements is 16 bits This data type cannot be assigned a numeric value range 22 103 Glossary 104 22
56. mperature control using a mixing air damper can be used For a mixing air controller there are normally 2 dampers a control damper for mixing the return air with the outside air and a control damper on the outside air inlet see examples on page 40 The control action on one damper is the reverse of the other In practical terms the controller output is sent to 1 damper only the other damper being controlled mechanically or electrically It therefore follows that the output sequences will depend on which damper is being controlled directly Also a minimum outside air flow is always guaranteed to provide some fresh air into the room Assuming an outside air minimum of 15 the output sequences would look like the following 00 37 MC_VAG m If the air mixer damper is controlled the sequences would be Figure 2 Air Mixing Damper Sequence 1 Outside air temp gt Return air temp X1 0 Y1 0 X2 100 Y2 85 Y A 100 T Y285 77 e Y1 X 0 100 X1 X2 Sequence 2 Outside air temp lt Return air temp X1 0 Y1 85 X2 100 Y2 0 Y A 100 T Y1 85 Y2 X 0 100 X1 X2 If the outside air damper is controlled the sequences would be Figure 3 Outside Air Damper Y1 15 Sequence 1 Outside air temp lt Return air temp X1 0 Y1 15 X2 100 Y2 100 A V2 100 pn Se Xx 0 100 X1 X2 Y1 100 Sequence 2 Outside air temp gt Retur
57. n air temp X1 0 Y1 100 X2 100 Y2 15 Y A N21 SYR FOSS Fes ese xX 0 100 X1 X2 38 00 MC_VAC 3 5 3 6 The reference values CMP_T1 and CMP_T2 will determine which of the sequences are activated as follows CMP_T1 gt CMP_T2 gt Sequence 1 is active CMP_T1 lt CMP_T2 gt Sequence 2 is active In order to get the desired control the comparison inputs should be connected as follows m If the air mixer damper is controlled CMP_T1 Outside air temperature CMP_T2 Return air temperature m If the outside air damper is controlled CMP_T1 Return air temperature CMP_T2 Outside air temperature Direct and Auxiliary control Direct or Auxiliary control is selected using the CASC parameter Direct control is specified by setting CASC 0 In this mode the Max Min selection is disable and the external input YEXT is ignored Auxiliary control is specified by setting CASC 1 In this mode the Max Min selection is enabled and the external input YEXT is compared to the PI controller output Manual operation There are 3 possible modes of manual operation which are specified by setting the mutually exclusive NORM MAN_CTR and MAN_SEQ parameters NORM mode NORM 1 The output of the Pl controller output is set to zero However the actual value forwarded to the output sequences depends on whether the controller is set up in Direct or Auxiliary mode In Direct mode t
58. n startup the controller output will drive a heating action which will reduce the chances of icing up in winter conditions However where the risk of icing up is great this mechanism should not be depended upon for freeze protection as unfavorable dynamics could result in the heating control valve closing In this case one should control the temperature manually by opening the heating control valve 100 on start up for a specific period of time before putting the controller into automatic and starting the fan Where a project uses multiple controllers that have the same behavior the user should define a consistent naming convention for the Concept project e g Y1 Y2 Y3 Heat Air Mix Cool Where a controller output is divided into multiple process outputs using the sequence functions one may have to take into account the fact that different process actuators have different gains As a result the controller gain may vary depending on the position of its output i e whether the output is driving a hot water control valve an air mixing damper or humidity control device The different actuator gains can be compensated by using the appropriate sequence layout 00 General information 2 3 3 Multi loop controls As well as single loops directly connected to process outputs cascaded loops where the output of one controller is connected as the setpoint of another controller are often required for HVAC systems The use of ca
59. ncreasing the inlet air temperature Conversely if the inlet air temperature is too warm the PI controller output will be increasingly more positive resulting in the opening of the control valve in order to divert a greater quantity of the cooler water to the outside air heat exchanger thereby decreasing the inlet air temperature 44 00 PI_VAC PI_VAC PI controller for air conditioning Brief description The PI_VAC basic function block is a general Pl controller designed for air conditioning applications It can be used for temperature control humidity control air mixing control or other general functions As it is a basic function block it consists of a PI controller only with no setpoint compensation output sequencing or other functions It is used extensively by the complex function blocks Where the standard complex function block library does not meet the requirements of a particular application the PI_VAC basic function block can be combined with other basic function blocks to create the user s own complex function block using the Concept Derived Function Block facilities The EFB provides the following m SP setpoint PV process variable and BIAS inputs Ability to operate in P or PI modes Bump less initialization of the contribution as well as bump less switching between and PI operation resetting the controller s gain in the form of GAIN or PROP with the possibility of us
60. nd by multiplying the absolute humidity scaled in g kg by 2 5 the resultant addition gives a good indication of the enthalpy content of the air in kJ kg In this case the built in hysteresis corresponds to 1 0 kJ kg In cases where an accurate value for hysteresis is not necessary the absolute humidity can be substituted by its corresponding dew point temperature This can be obtained by the use of WASH_VAC feeding the measured relative humidity to SP_RH and the measured temperature Ta to SP_RT The resulting SP_TW replaces in this case the term 2 5Xx H Ta SP_TW SP_TW represents a nonlinear but fixed function or the unknown absolute humidity Because both values of H from RETURN AIR and OUTSIDE AIR are calculated in the same way the comparison of both values does not need to take care that these calculated values themselves are nonlinear to the true H values During the first execution cycle of the function block the hysteresis is initialized on the assumption that CMP_T1 lt CMP_T2 If after the first calculation cycle the comparison result is within the hysteresis band the initial switching status is retained Output Sequences Note Only one output sequence is specified by the user The function block will then calculate the reversed sequence when the control direction is switched The sequence specified must have an increasing slope i e Y2 gt Y1 In order to understand how the output sequencing works the example of te
61. nd underscore symbols that must begin with a letter or underscore symbol for instance the name of a function block type an instance a variable or a section Letters from National character sets e g 6 6 can be used except in project and DFB names Underscore symbols in identifiers are significant for example A_BCD and AB_CD will be interpreted as different identifiers Several leading and multiple underscore symbols sequentially are not allowed Spaces are not allowed in identifiers Upper or lower case is not significant for example ABCD and abcd will be interpreted as the same identifier Key words are not allowed as identifiers IIR Filter Infinite Impuls Response Filter Infinite Impulse Reponse Filter IL refer to Instruction List IL 22 91 Glossary Initial Step Starting step The starting step of a sequential chain One initial step must be defined in each sequence This initial step starts the sequence when first invoked Initial Value The value assigned to a variable at the start of a program Input bits 1x references The 1 0 state of input bits is controlled by process data that are received by the CPU from an input unit Note The x placed after the first digit of the reference type represents a five digit memory location in user data memory e g reference 100201 signifies an input bit at address 201 of State RAM Input parameter input At the invo
62. nor can derived functions be defined in the current version There is a distinction between Local and Global DFBs DFB see Derived function block DINT DINT represents the data type double integer It is entered as an integer literal base 2 literal base 8 literal or base 16 literal The length of data elements is 32 bits The value range for variables of this data type is from 2 exp 31 to 2 exp 31 1 86 22 Glossary Direct representation A form of representation for a variable in the PLC program from which the allocation to the logical memory location and indirectly its physical memory location can be directly determined Distributed network Distributed programming in the Modbus Plus network facilitates maximum performance during data transfer and in special requirements to links Programming of a distributed network is easy Setting up the network does not require additional ladder diagram logic By making the appropriate entries in the Peer Cop processor all requirements for data transfer are taken care of Dummy An emtpy file that contains a header with genenral file information e g author editing date EFB name etc The user has to complete this Dummy file by editing Duration literals The units allowed for durations TIME are days D hours H minutes M seconds S and milliseconds MS or combinations thereof The duration must be identified by the prefix t T time or TIME
63. nti Windup Reset AWR Manual adjustment of either the Pl controller output or the individual sequence outputs Y1 and Y2 using percentages When the controller output is manually adjusted the EFB tracks the contribution in order to provide bumpless switching back to automatic mode The display of the P and PI controller errors SP PV Note Additional parameters EN and ENO should not be configured You will find this EFB in the HVAC library 32 00 MC_VAC 2 Representation 2 1 Symbol MC_VAC REAL sp y REAL REAL cv Y_PC REAL REAL Pv ERR REAL REAL YEXT REAL cMP_T1 REAL cmMp_H1 REAL CMP_T2 REAL CMP_H2 BOOL NORM BOOL MAN_CTR BOOL MAN_SEQ REAL YMAN_PC PARA_MC PARA 33 MC_VAG 2 2 Parameter Specifications Table 1 MC_VAC Parameter Data Type Meaning SP REAL Setpoint CV REAL Command variable PC REAL Actual value YEXT REAL Manipulated variable of higher level controller in the case of ca scade mode CMP_T1 REAL Reference value T1 CMP_H1 REAL Reference value H1 CMP_T2 REAL Reference value T2 CMP_H2 REAL Reference value H2 NORM BOOL Basic setting MAN_CTR BOOL MANUAL for controller MAN_SEQ BOOL MANUAL for sequence YMAN_PC REAL Total manual manipulated variable as a or sequence manual manipulated variable as a PARA PARA_MC Parameter st
64. old on a real input variable m The possibility to set the control direction by selecting any threshold values Positive and negative output signals Additional parameters EN and ENO may be configured You will find this EFB in the HVAC library Representation Symbol THRS_VAC REAL x YP BOOL REAL THRS_ON YN BOOL REAL THRS_OFF Parameter Specifications Parameter Data Type Meaning X REAL Input variable THRS_ON REAL Energize limit value THRS_OFF REAL Switch off limit value YP BOOL Positive reply signal YN BOOL Negative reply signal 00 57 THRS_VAC 3 1 Detailed description Basic Operation The block monitors an input variable X for 2 limits thresholds When the on threshold THRS_ON is reached the output YP is set equal to one and when the off threshold THRS_OFF is reached the output YP is set to zero The output YN is set as the complement of YP The user is free to set any values for the thresholds The behavior of the outputs based on the relative sizes of the 2 thresholds is shown in Figure 1 Figure 1 Hysteresis and switching function of THRS_VAC with different configurations a THRS_ON gt THRS_OFF b THRS_ON lt THRS_OFF c THRS_ON THRS_OFF YP YN YP YN YP YN A A A THRS_ON THRS_OFF 1 att 1 Y ij A A ij l X X x 0 p 0 0 THRS_OFF THRS_ON THRS_ON THRS_OFF In t
65. oller total output or the individual sequence outputs Y1 and Y2 using percentages When the controller output is manually adjusted the EFB tracks the contribution in order to provide bump less switching back to automatic mode m The display of the P and PI controller errors SP PV Note Additional parameters EN and ENO should not be configured You will find this EFB in the HVAC library 59 UC2_VAC 2 Representation 2 1 Symbol UC2_VAC REAL sP y1 REAL REAL cv y2 REAL REAL PV BOOL NORM BOOL MAN_CTR BOOL MAN_SEQ REAL YMAN_PC REAL YMAN1_PC Y1_PC REAL REAL YMAN2_PC Y2_PC REAL PARA_UC2 PARA ERR REAL 2 2 Parameter Specifications Table 1 UC2_VAC Parameter Data Type Meaning SP REAL Setpoint CV REAL Command variable PV REAL Actual value NORM BOOL Basic setting MAN_CTR BOOL MANUAL for controller MAN_SEQ BOOL MANUAL for sequences YMAN_PC REAL Total manual manipulated variable as a for controller YMAN1_PC REAL Individual manual manipulated variable as a for 1 Sequence YMAN2_PC_ REAL Individual manual manipulated variable as a for 2 Sequence PARA PARA_UC2 Parameter structure Y1 REAL Manipulated variable Output variable 1 Y2 REAL Manipulated variable Output variable 2 Y1_PC REAL Manipulated variable Output variable 1 as a Y2_PC REAL Manipulated variable
66. on A section for instance can be used to describe the mode of operation of a technological unit such as a motor A program or DFB consists of one or several sections Sections can be programmed with the IEC programming languages FBD and SFC Within a section only one of the listed programming languages can be used In Concept each section has its own document window However to have a better overview it is recommended to subdivide a large section into several smaller ones The scroll bar is used to move around within a section Separator format 4 00001 A colon separates the first digit of the reference from the following five digit address Sequential Function Chart SFC The SFC language elements allow the subdividing of a PLC program organization unit into a set of steps and transitions which are interconnected through directional links Each step is associated with a set of actions and each transition is linked with a transition condition Serial ports Serial ports COM transfer information bit by bit SFC see Sequential Function Chart ST refer to Structured Text ST 100 22 Glossary Standard format 400001 The five digit address is placed immediately after the first digit of the reference Statement ST Statements are the commands of the programming language ST Statements must end with semi colons Several statements separated by semi colons may be placed into one line State RAM
67. oning with 2 outputs 17 CC3_VAC Cascade controller for air conditioning with 3 outputs 24 MC_VAC Air mix controller for air conditioning with one output 32 PI_VAC PI controller for air conditioning 0 00 cece cece ee 45 SEQ_VAC Scaling Sequence Block for Air Conditioning 05 49 SW_VAC Summer Winter Setpoint Compensation for Air Conditioning 54 THRS_VAC Threshold Switch with Hysteresis for Air Conditioning 57 UC2_VAC Universal PI controller for air conditioning with 2 outputs 59 UC3_VAC Universal PI controller for air conditioning with 3 outputs 65 VQ_VAC Measured Value Deadband Block for Air Conditioning 71 WASH_VAC Basic Washer Block for Air Conditioning eee e eee 74 Glossary cora e ae aide Ret ne ie ee ets 79 00 Contents 00 About ul o Chap 1 Chap 2 EFB descriptions Glossary This documentation helps you to configure EFBs for ventilation and air conditioning VAC which can be loaded into Concept at a later stage Layout of the documentation Contains general information on assigning parameters to EFBs Contains general information on the use of EFBs for air conditioning Includes a description of EFBs in alphabetical order according to their respective abbreviations Includes a glossary in alphabetical order
68. ontrol actuators will depend on the output sequence parameters MAN_CTR mode MAN_CTR 1 The output of the PI controller is set equal to the user specified parameter YMAN_PC Again the output sequences are active in this mode and therefore the actual values of Y1 and Y2 that are output to the control actuators will depend on the output sequence parameters MAN_SEQ mode MAN_SEQ 1 The outputs Y1 and Y2 are set to the values specified by the parameters YMAN1_PC and YMAN2_PC i e Y1_PC YMAN1_PC and Y2_PC YMAN2_PC In MAN_CTR mode the contribution of the Pl controller is tracked so that a bumpless transfer back to automatic mode may be carried out In NORM and MAN SEQ modes the contribution is set to zero 63 UC2_VAC 3 4 Output Parameters The UC2_VAC outputs Y1 and Y2 are available in real or percentage form Y1 Y2 Y1_PC and Y2_P2 The percentage values specified for the manual control of outputs YMAN_PC YMAN1_PC and YMAN2_PC refer to the specified range of the appropriate output For example the variable YMAN_PC sets the total output of the PI_VAC basic function block The range of this output is specified by the parameters YMIN 0 and YMAX 100 The variables YMAN1_PC and YMAN2_PC set the outputs of the two SEQ_VAC blocks the ranges of which are specified by their corresponding ordinate vales Y1 Y2 where Y1 and Y2 refer to the SEQ_VAC ordinates not the actual outputs Y1 and Y2 of the two SEQ_
69. perature humidity as process variable and an inner PI loop that controls the temperature humidity of the inlet air supplying the room The EFB has a fixed structure where the setpoint of the P controller is fed forward and added to the P controller output to form the setpoint of the Pl controller The output of the Pl controller has 3 output sequences Y1 Y2 and Y3 The operation of CC3_VAC is identical to CC2_VAC the only difference being the additional output The EFB provides the following Winter summer setpoint compensation as per DIN 1946 part 2 Full four quadrant operation of the output sequence scaling The display of output variables as percentages Upper and lower limits on outputs Presetting the controllers gains in the form of GAIN or PROP with the possibility of using negative values for switching the control direction Operation with Anti Windup Reset AWR Manual adjustment of either the Pl controller output or the individual sequence outputs Y1 and Y2 using percentages When the controller output is manually adjusted the EFB tracks the contribution in order to provide bump less switching back to automatic mode m The display of the P and PI controller errors SP PV Note Additional parameters EN and ENO should not be configured You will find this EFB in the HVAC library 24 00 CC3_VAC 2 1 Representation Symbol REAL REAL REAL REAL BOOL BOOL
70. perature transmitter and whose output is used to control the preheat and cooling coils In other words this PI controller maintains the appropriate dewpoint temperature off the washer In addition a temperature controller CC2_VAC is used to control the room and inlet air temperature by driving the preheat reheat coils and cooling coil A minimum select is used to switch between the humidity and temperature controller The controller RK3 is configured as a P controller only with a PV set to zero and the gain set to one In this way it simply acts as an output sequencer that divides the setpoint input between the preheat and cooling coils The washer outlet temperature is set to a range of 5 to 30 degrees Celsius to prevent icing up or overheating of the washer Figure 2 Integration of WASH_VAC in a room inlet air_cascade control system Mixed_Preheating Cool Washer Reheating Air 100 R H wa Inlet Air M31 Y31 M32 Y32 M33 Y33 A A amp Be B82 oC oC r 4 1 UC2_VAC 1 Humidity RK1 controller WASH VAC PV UC2_VAC Partition y1 PI SP R H RK3 y2 sp SW_VAC P PV MIN SPRT CVje AL Yi SP y1 RK2 ie Ki u 5 Pv N NEJ SP lt 0 0 gt GAIN lt 0 0 gt Pv2 a SP_SPCV lt 1 gt CC2_VAC Temperature controller Sequences Y RK1 EK PI 100 50 00 77
71. printed text is larger than its width Prototype file Concept EFB The prototype file contains all prototypes of the respective functions A type definition of the internal state structure is also included if available Q R REAL REAL represents the data type floating point number It is entered as a real literal or as a real literal with exponent The length of data elements is 32 bits The value range for variables of this data type is from 8 43E 37 to 3 36E 38 98 22 Glossary Real literals Real literals are used to indicate floating point values in the decimal system Real literals are identified by a decimal point The values can have a preceding sign Individual underscore symbols _ between the numbers have no significance Example 12 0 0 0 0 456 3 14159 26 Real literals with exponent Real literals with exponent are used to indicate floating point values in the decimal system Real literals with exponent are identified by a decimal point The exponent indicates the power of ten for the multiplication of the previous number in order to arrive at the value that will be displayed The values can have a preceding sign Individual underscore symbols _ between the numbers have no significance Example 1 34E 12 or 1 34e 12 1 0E 6 or 1 0e 6 1 234E6 or 1 234e6 Reference Every direct address is a reference beginning with an identification character that denotes whether thi
72. put of the PI_VAC basic function block The range of this output is specified by the parameters YMIN 0 and YMAX 100 The variables YMAN1_PC YMAN2_PC and YMAN3_PC set the outputs of the two SEQ_VAC blocks the ranges of which are specified by their corresponding ordinate vales Y1 Y2 where Y1 and Y2 refer to the SEQ_VAC ordinates not the actual outputs Y1 Y2 and Y3 of the two SEQ_VAC blocks It is important to note that the smaller value of Y1 and Y2 is always equated to 0 and the greater value to 100 In other words the percentage value is related to the size of the output variable Y irrespective of its direction Y1 lt Y2 gt 0 100 Y1 Y2 Y1 gt Y2 gt 0 100 Y2 Y1 For more information on the operation of the SEQ_VAC block please refer to the respective description see page 49 70 00 VQ_VAC 2 1 2 2 VQ_VAC Measured Value Deadband Block for Air Conditioning Brief description The VQ_VAC basic function block performs the function of adding a deadband DX to an input variable X If X changes by more than the amount DX the output Y is updated with the value of X The function block may be used to Stabilize a process variable that has a certain amount of noise e g room pressure measurement Seta preset minimum modification that must be made to a value before it will be changed m Provide a dynamic matching of the range of a minimum modification around a curren
73. ructure Y REAL Manipulated variable Output variable Y_PC REAL Manipulated variable Output variable as a ERR REAL System Deviation Table 2 PARA_MC Element Data Type Meaning CASC BOOL Direct cascade mode SP_SPCV BOOL Setpoint setpoint command variable MIN BOOL Max min switch max 0 PI Controller YMAX REAL Upper limit of manipulated variable YAU always 0 GAIN REAL Controller gain PROP REAL Proportional value PREF REAL Proportional value reference Tl TIME Reset time Output sequence x1 REAL 1 Abcissa value Y1 REAL 1 Ordinate value X2 REAL 2 Abcissa value Y2 REAL 2 Ordinate value 34 00 MC_VAC 3 Detailed description 3 1 EFB structure A block diagram representation of the CC2_VAC complex function block is shown in Figure 1 It is made up of the following basic function blocks m SW_VAC Summer winter compensation see page 54 m PIVAC Basic PI controller for HVAC applications see page 45 THRS_VAC Limit Selector with hysteresis see page 57 m SEQ VAC Output Sequence scaling module see page 49 Figure 1 Controller structur Unbroken line Outside air damper activated sw VAC YMAN_PC Broken
74. s YMIN2 and YMAX2 have been set to values that do not enclose zero the output will be set to the value of YMIN2 and YMAX2 that is closest to zero In other words Y YMAX2 if YMAX2 lt 0 AND YMIN2 lt 0 Y YMIN2 if YMAX2 gt 0 AND YMIN2 gt 0 Again the actual values of Y1 Y2 and Y3 that are output to the control actuators will depend on the output sequence parameters MAN_CTR mode MAN_CTR 1 The output of the PI controller is set equal to the user specified parameter YMAN_PC Again the output sequences are active in this mode and therefore the actual values of Y1 Y2 and Y3 that are output to the control actuators will depend on the output sequence parameters MAN_SEQ mode MAN_SEQ 1 The outputs Y1 Y2 and Y3 are set to the values specified by the parameters YMAN1_PC YMAN2_PC and YMAN3_PC i e Y1_PC YMAN1_PC Y2_PC YMAN2_PC and Y3_PC YMAN3_PC In MAN_CTR mode the contribution of the Pl controller is tracked so that a bumpless transfer back to automatic mode may be carried out In NORM and MAN SEQ modes the contribution is set to zero 69 UC3_VAC 3 4 Output Parameters The UC3_VAC outputs Y1 Y2 and Y3 are available in real or percentage form Y1 Y2 Y3 Y1_PC Y2_PC and Y3_PC The percentage values specified for the manual control of outputs YMAN_PC YMAN1_PC YMAN2_PC and YMAN3_PC refer to the specified range of the appropriate output For example the variable YMAN_PC sets the total out
75. s a whole A program is further refined by IEC language elements Program cycle scan A program cycle consists of reading the inputs processing of program logic and writing of the outputs 22 97 Glossary Programming unit Hardware and software that supports programming configuring testing delivering and troubleshooting in PLC applications as well as in distributed system application in order provide for source documentation and archiving backup The programming unit can also be used for process visualization if necessary Program organization unit A function a function block or a program This term can refer either to a type or to an instance Project General term for the highest level of a software tree structure which defines the overall project name of a PLC application After the definition of the project name the system configuration and the control programm can be saved with this name All data which is created while creating the configuration and the program are belonging to project for this special automation task General term for the complete set of programming and configuration information in the project data base which represents the source code that describes the automation of a system Project data base The data base in the programming unit that contains the configuration information for a project Portrait format Portrait vertical format means that the height of the page when looking at the
76. s a ladder diagram interface so that electricians do not need to learn an unfamiliar programming language to implement a control program The construction of the actual ladder diagram allows the electrical elements to be connected in such a way as to create control output dependent on some logical power flow through the electrical objects used represent the previously required condition of a physical electrical device In a simple form the user interface is a video display produced by the PLC programming application that establishes a vertical and horizontal grid into which programming objects are arranged The diagram has power available at the left side of the grid and when connected to objects that are activated the power will flow from left to right Landscape format Landscape horizontal format means that the page width when looking at the printed text is larger than its height Language element Every basic element in one of the IEC programming languages e g a step in SFC a function block instance in FBD or the initial value of a variable 94 22 Glossary LD Refer to Ladder Diagram LD Ladder Logic 984 LL Library A collection of software objects intended for reuse when programming new projects or even to build new libraries Examples are the library of Elementary function block types EFB libraries can be subdivided into groups Link A control or data flow connection between graphical objects e g steps
77. s always equated to 0 and the greater value to 100 In other words the percentage value is related to the size of the output variable Y irrespective of its direction Y1 lt Y2 gt 0 100 Y1 Y2 Y1 gt Y2 gt 0 100 Y2 Y1 For more information on the operation of the SEQ_VAC block please refer to the respective description see page 49 00 31 MC_VAG MC_VAC Air mix controller for air conditioning with one output Brief description The MC_VAC module is a controller designed for applications that require switching of the controller direction and maximum minimum selection of outputs Examples of such applications would be air mixing controls where the control direction will depend on the relative values of the outside air temperature and return air temperature or heat exchanger controls used in energy conservation schemes The EFB provides the following Winter summer setpoint compensation as per DIN 1946 part 2 Full four quadrant operation of the output sequence scaling The display of output variables as percentages Upper and lower limits on outputs Presetting the controllers gains in the form of GAIN or PROP with the possibility of using negative values for switching the control direction Control reversal using comparison inputs with built in hysterisis Selection of operating mode as a Direct Controller or Auxiliary Controller with Max Min selection Operation with A
78. s is an input or an output and whether it is a bit or a register References that begin with the identification number 6 represent registers in the extended memory of State RAM Ox range Output holding bits 1x range Input bits 3x range Input registers 4x range Output holding registers 6x range register in extended memory Note The x placed after the first digit of each reference type represents a five digit memory location in user data memory for example reference 400201 means this is a 16 bit output or holding register at address 201 of State RAM Registers in the extended memory 6X Reference 6x References are marker words in the extended memory of the PLC They can only be used with LL984 user programs with a CPU 213 04 or CPU 424 02 RIO Remote I O Remote I O refers to physical location of I O point control units with regard to the Processor controlling them Remote I O are connected to the control unit through a wired communications cable 22 99 Glossary RTU mode Remote Terminal Unit The RTU mode is used for communication between the PLC and an IBM compatible PC RTU works with 8 data bits Runtime Error Errors that occur while the program is processing on the PLC in SFC objects e g Steps or FFBs These are for instance value range overflows in counters or time errors in steps S SA85 module The SA module is a Modbus Plus adapter for IBM AT or compatible computers Secti
79. scaded controllers not only gives improved dynamics it also results in a clearer and easier to understand layout of the HVAC controls The output sequence functions allow the user to design a wide variety of control options for his HVAC strategy Examples of output sequencing are given in Figure 1 Y refers to the PI controller output while Y1 Y2 and Y3 refer to the final outputs from the output sequencing which are either sent directly to the process actuators or to other programming controllers functions 00 13 General information Figure 1 Examples of sequences with direct output of output values as manipulated variables a Single manipulated variable Y1 A 100 50 100 pY 100 0 100 100 0 b Double manipulated variable 0 heat 50 heat 100 heat 100 0 0 100 0 150 0 50 0 0 50 0 200 0 100 0 0 0 Triple manipulated variable 0 ML 100 ML l Y3 100 Y2 y1 Y3 400 Y2 Y1 Air mix Cool Air mix gt Y 67 0 0 0 67 0 133 0 133 0 67 0 0 0 67 0 EFB Descriptions ree S575 The EFB descriptions are arranged alphabetically according to their abbreviations 00 00 CC2_VAC CC2_VAC Cascade controller for air conditioning with 2 outputs 1 Brief description The CC2_VAC module is a cascade controller used to provide temperature or humidity control of th
80. specified by setting the mutually exclusive NORM MAN_CTR and MAN_SEQ parameters NORM mode NORM 1 The output of the Pl controller output is set to zero The zero value is fed to the output sequences that are active in NORM mode As a result the actual values of Y1 and Y2 that are output to the control actuators will depend on the output sequence parameters In the case where the controller output limits YMIN2 and YMAX2 have been set to values that do not enclose zero the output will be set to the value of YMIN2 and YMAX2 that is closest to zero In other words Y YMAX2 if YMAX2 lt 0 AND YMIN2 lt 0 Y YMIN2 if YMAX2 gt 0 AND YMIN2 gt 0 Again the actual values of Y1 and Y2 that are output to the control actuators will depend on the output sequence parameters MAN_CTR mode MAN_CTR 1 The output of the PI controller is set equal to the user specified parameter YMAN_PC Again the output sequences are active in this mode and therefore the actual values of Y1 and Y2 that are output to the control actuators will depend on the output sequence parameters MAN_SEQ mode MAN_SEQ 1 The outputs Y1 and Y2 are set to the values specified by the parameters YMAN1_PC and YMAN2_ PC i e Y1_PC YMAN1_PC and Y2_PC YMAN2_PC In MAN_CTR mode the contribution of the Pl controller is tracked so that a bumpless transfer back to automatic mode may be carried out In NORM and MAN SEQ modes the contribution is set to zero 22
81. sted the EFB tracks the contribution in order to provide bump less switching back to automatic mode m The display of the P and PI controller errors SP PV Note Additional parameters EN and ENO should not be configured You will find this EFB in the HVAC library 65 UC3_VAC 2 Representation 2 1 Symbol UC3_VAC REAL SP Y1 REAL REAL cv y2 REAL REAL Pv Y3 REAL BOOL NORM BOOL MAN_CTR BOOL MAN_SEQ REAL YMAN_PC REAL YMAN1_PC Y1_PCc REAL REAL YMAN2_PC Y2_PC REAL REAL YMAN3_PC Y3_PCt REAL PARA_UC3 PARA ERR REAL 2 2 Parameter Specifications Table 1 UC3_VAC Parameter Data Type Meaning SP REAL Setpoint CV REAL Command variable PV REAL Actual value NORM BOOL Basic setting MAN_CTR BOOL MANUAL for controller MAN_SEQ BOOL MANUAL for sequences YMAN_PC REAL Total manual manipulated variable as a for controller YMAN1_PC_ REAL Individual manual manipulated variable as a for 1 Sequence YMAN2_PC_ REAL Individual manual manipulated variable as a for 2 Sequence YMAN3_PC_ REAL Individual manual manipulated variable as a for 3 Sequence PARA PARA_UC3 Parameter structure Y1 REAL Manipulated variable Output variable 1 Y2 REAL Manipulated variable Output variable 2 Y3 REAL Manipulated variable Output variable 3 Y1_PC REAL Manipulated variable Outp
82. t input variable Additional parameters EN and ENO may be configured You will find this EFB in the HVAC library Representation Symbol VQ_VAC REAL x y REAL REAL DX Parameter Specifications Parameter Data Type Meaning X REAL Input variable DX REAL Minimum modification input Y REAL Output variable 00 71 VQ_VAC 3 Detailed description 3 1 Basic Operation The VQ_VAC basic function block updates an output Y with an input value X when X changes by an amount greater than the value set at the input DX During the first cycle the output Y is set to equal the value of input X Y will then retain this value until Xnew lt X DX or Xnew gt X DX At which point Y Xnew This is shown in Figure 1 Figure 1 Quantization diagram VQ_VAC vA pr oae Y i 1 ie AS lt q 1 Y i E va Eas i ZAT X i n X i X i 1 x 2 DX A Quantization diagram in the case of slow movement of the working point AP from an input value X i n lying behind n steps of the current input value X i B New quantization diagram in the case of stepped modification from X i to X i 1 if the jump is gt DX The function block can be used to either stabilize a varying input or to set a dynamic deadband range around a value The range is dynamic in the sense that it is not 72 00 VQ_VAC 3 2 absolu
83. t to note that the smaller value of Y1 and Y2 is always equated to 0 and the greater value to 100 In other words the percentage value is related to the size of the output variable Y independent of the direction increasing decreasing of the sequence This is shown in Figure 1 and Figure 2 Figure 1 Ascending sequence 1 Quadrant Y W Output value range D Input definition range X i Y i current values Module inputs outputs X 2173 0 X1 1000 0 Y1 400 0 X2 3000 0 Y2 8000 0 Y 4857 4 Y_PC 58 65 00 51 SEQ_VAC Figure 2 Descending sequence 1 Quadrant W Output value range D Input definition range X i Y i current values Module inputs outputs X 117 0 X1 100 0 Y1 7500 0 X2 450 0 Y2 1250 0 Y 7196 428 Y_PC 95 143 3 3 Manual Operation The SEQ_VAC block may be put in manual by setting MAN 1 In manual mode the percentage value specified by YMAN_PC is written to the block s output i e Y_PC YMAN_PC The real value Y is determined by the scaling of the sequence 52 00 SEQ_VAC Example An analogue input 4 20 ma must be converted to a REAL value corresponding to a temperature range of 20 to 80 degrees Celsius The corresponding parameters are X1 6400 0 accordingly 20 degrees C X2 32000 0 accordingly 80 degrees C Y1 20 0 accordingly 20 degrees C Y2 80 0 accordingly 80 degrees C F
84. take over from the inlet air controller to maintain the minimum water temperature through the return air heat exchanger thereby preventing freezing of any condensation that may have occurred The inlet air controller controls the inlet air temperature An MC_VAC block is used for the anti freeze controller and is run in CASCADE mode The output of the inlet air controller is fed as the input Yext to the anti freeze controller thereby controlling the heat exchanger control valve If T OUTSIDE lt T_RETURN sequence B is used In this case it can be seen that if the inlet air temperature is too low the PI controller output whose gain is negative will be increasingly negative opening the control valve in order to divert a greater quantity of warmer water to the outside air heat exchanger thereby increasing the inlet air temperature Conversely if the inlet air temperature is too warm the PI controller output will be increasingly more positive resulting in a closing of the control valve in order to divert a smaller quantity of the warmer water to the outside air heat exchanger thereby decreasing the inlet air temperature If T OUTSIDE gt T_RETURN sequence A is used In this case it can be seen that if the inlet air temperature is too low the PI controller output whose gain is negative will be increasingly negative closing the control valve in order to divert a smaller quantity of cooler water to the outside air heat exchanger thereby i
85. te but is relative to the input value X One example of where it could be used is to set a trigger point relative to a controller setpoint which may itself be changed by an operator Where the block is used to manipulate a process variable to a controller care must taken by performing on site tests that the stability of the control loop is not adversely affected by the introduced deadband Parameters The input X and output Y are real variables The variable DX must be set as a positive real value The scaling basic function block SEQ_VAC may be used before or after VQ_VAC in order to scale the measured value X Y 00 73 WASH_VAC 2 1 2 2 WASH_VAC Basic Washer Block for Air Conditioning Brief description The WASH_VAC basic function block provides the Calculation of a dew point value SP_TW based upon a dry bulb temperature SP_T and relative humidity value SP_RH One possible application for the WASH_VAC block is the possibility to control a room s humidity by regulating the outlet temperature of a washer Note It can only be used with air washers that guarantee a 100 saturated air at the washer outlet In other words the block assumes that the outlet washer dry bulb temperature is equivalent to the dew point temperature Such an approach has the advantage of controlling a humidity using a cost effective temperature sensor rather than a more expensive humidity sensor Additional parameters EN and ENO may b
86. ted variable YMAX REAL Upper limit manipulated variable YMIN REAL Lower limit manipulated variable GAIN REAL Controller gain PROP REAL Proportional value PREF REAL Proportional value reference Tl TIME Integral Time Y REAL Manipulated variable ERR REAL Control deviation QMAX BOOL Upper limit of signalling device reached QMIN BOOL Lower limit of signalling device reached 46 00 PI_VAC 3 1 3 2 Detailed description Parameter Specifications SP PV BIAS The setpoint SP and process variable PV are connected directly to the function block as real values The controller error is calculated as ERR SP PV The error value is available for display A BIAS value may also be specified as a real value This BIAS value is added to the result of the PI calculation In this way the user can ensure that the controller output is biased with a specific value during the first cycle This is shown in Figure 6 GAIN PROP PREF TI The controller gain can be specified by either setting a value for the GAIN or alternatively by specifying the proportional rate using the PROP and PREF parameters as follows m f GAIN is not equal to zero then the GAIN mode is activated In this case the controller output for P only control is then calculated as Y GAIN SP PV A negative value of GAIN may be specified to reverse the action of the controller m If GAIN 0 and PROP is not equal to zero then the P
87. ted without an error the value of ENO is automatically set to 1 Should an error occur while these algorithms are executing ENO is automatically set to 0 The output behavior of the FFBs is independent of the FFBs being invoked without EN ENO or with EN 1 If display of EN ENO is turned on the EN input must be definitely connected Otherwise the FFB will never be executed The configuration of EN and ENO is turned on or off in the dialog box of the block properties The dialog box is invoked with the menu commands Objects gt Properties or by double clicking at an FFB Errors If an error is detected while an FFBs or a Step is processing e g unauthorized input values or time errors an error message will appear that can be viewed with the menu command Online gt Online events The ENO output for FFBs is set to 0 Evaluation The process used to establish a value for a function or for the outputs of a function block during program execution Expression Expressions consist of operators and operands 88 22 Glossary F FB see Function Block instance FBD see Function Block Diagram FFB Functions Function blocks Collective term for EFB Elementary functions Function blocks and DFB Derived function blocks FIR Filter Finite Impulse Response Filter Finite Impluse Response Filter Formal parameters Input output parameters that are used within the logic of an FFB and are brought o
88. teral The length of data elements is 32 bits The value range for variables of this data type is from 0 to 2 exp 32 1 The unit for the data type TIME is 1 ms Token The network token controls the temporary possession of transmittal rights by an individual node The token passes the nodes in a rotating ascending address sequence All nodes are tracking the token rotation and can receive any data that is sent along Traffic Cop The Traffic Cop is an I O map which is generated from the user I O map The Traffic Cop is scheduled in the PLC and contains e g status information in addition to the user I O map Transition The condition whereby control passes from one or more predecessor steps to one or more successor steps along a directed link 102 22 Glossary U UDEFB user defined elementary functions function blocks Functions or function blocks created in C which Concept makes available in libraries UDINT UDINT represents the data type unsigned double integer It is entered as an integer literal base 2 literal base 8 literal or base 16 literal The length of data elements is 32 bits The value range for variables of this data type is from 0 to 2 exp 32 1 UINT UINT represents the data type unsigned integer It is entered as an integer literal base 2 literal base 8 literal or base 16 literal The length of the data elements is 16 bits The value range for variables of this data type is fro
89. tion blocks implement in the form of EFB s the more complex functions found in controllers which are frequently used in air conditioning systems They are built using the basic function blocks Table 2 ComplexFunctions Blocks Function Block Description CC2_VAC Cascade Controller for Air Conditioning with 2 Outputs CC3_VAC Cascade Controller for Air Conditioning with 3 Outputs MC_VAC Air Mix Controller for Air Conditioning with 1 Output UC2_VAC PI Controller for Air Conditioning with 2 Outputs UC3_VAC PI Controller for Air Conditioning with 3 Outputs Note It is strongly recommended that the user familiarizes himself with the operation of the basic function blocks before reading the complex function block sections Scaling and descaling within a control program General instructions Basically a control set up consists of 3 parts see Figure 2 The scaling of input variables m The controller m The sequencing of output variables Figure 2 Control Set up Input Output Scaling I Controller _J Sequencing Output Sequencing is used to take the controller single output split it into several parts and to scale the resultant outputs It can be used for example to split the controller output amongst multiple actuators For the purposes of the Concept HVAC library the controller and output sequencing are combined into one EFB The scalin
90. tructions are the operations of the programming language IL Each instruction begins in a new line and is followed by an operator sometimes with modifier and if required for a respective operation by one or several operands If several operands are used they will be separated by commas Instruction LL984 Programming for electrical controls involves a user who implements Operational Coded instructions in the form of visual objects organized in a recognizable ladder form The program objects designed at the user level is converted to computer usable OP codes during the download process The Op codes are decoded in the CPU and acted upon by the controllers firmware functions to implement the desired control Instruction list IL is a text language as per IEC 1131 that displays operations such as conditional or unconditional calls of function blocks and functions conditional or unconditional jumps etc through instructions INT INT represents the data type integer It is entered as an integer literal base 2 literal base 8 literal or base 16 literal The length of the data elements is 16 bits The value range for variables of this data type is from 2 exp 15 to 2 exp 15 1 Integer Literals Integer literals are used to denote integer values in the decimal system The values can have a preceding sign Individual underscore symbols _ between the numbers have no significance Example 12 0 123_456 986
91. unction block description for detailed information Figure 1 Controller structure SW_VAC YMAN1_PC SP Y1 apyl naa m Y1_PC O YMAN2_PC PI_VAC sas PI_VAC SP a e Y2 D gt gt e PV1 S H Y2_ PC Pv2 YMAN3_PC SEQ_VAC YMAN_PC R a se NORM gt Module m A ee control A MAN_CTR MAN_SEQ MEE PARA_CC3 Module parameters While the CC3_VAC function block can be used for both temperature or humidity control the remainder of this description refers to temperature control only 28 00 CC3_VAC 3 2 Basic Operations The setpoint for the CC3_VAC function block is fed to the P controller via the summer winter compensation block SW_VAC description see page 54 The output of the SW_VAC block is fed not only to the setpoint of the room P controller but also to its BIAS input In this way the P controller setpoint is added to the P controller output which is equal to the P controller error amplified by the controller gain and the result is fed as setpoint to the inlet air Pl controller This is shown in Figure 2 Figure 2 Diagram of setpoint formation PV1 Room temperature Room air P contribution adjustable from 0 to the point of instability Inlet a
92. used e g 12 345 67 Additional documentation Description Type Concept Installation instructions 840 USE 502 00 Concept User Manual Vol 1 Vol 2 840 USE 503 00 IEC block library Concept Vol 1 Vol 2 Vol 3 840 USE 504 00 Modicon TSX Quantum PLC Series Hardware User Manual 840 USE 100 00 Modbus Plus Network User Manual 890 USE 100 00 Modlink User s Guide Modicon GM MLNkK 001 User s Guide Modicon IBM Host Based Devices GM HBDS 001 User s Guide BM85 Modbus Plus Bridge Multiplexer GM BM85 001 Planning and Installation Guide Modicon Quantum Hot Standby System 840 USE 106 00 Quantum Ethernet TCP IP Module User Guide 890 USE 107 00 Note on validity This documentation applies to Concept Version 2 5 2 6 under Microsoft Windows 95 Windows 98 Windows NT or Windows 2000 Note You will find additional up to date instructions in the Concept file called README PDF 00 About 00 Parameter assignment 1 This chapter contains general notes for parameter assignment of the function and function blocks FFBs 00 Parameter assignment 1 1 General Information Each FFB is composed of an operation operands required for the operation and an instance name function number Figure 1 FFB Parameter assignment with the function block SW_VAC as an example e g on
93. ut of the FFB as inputs outputs Function FUNC A program organization unit which when executed will yield exactly one data element A function has no internal state information Multiple calls to the same function with the same input parameter values will always yield the same output values Details about the graphical form of function calls can be found in the definition Function Block instance Contrary to function block calls function calls have only one single unnamed output because its name is the name of the function itself In FBD each call is identified by a unique number above the graphical block this number is automatically created and cannot be changed Function block diagram FBD One or several sections containing graphically represented networks consisting of functions function blocks and links Function block instance FB A function block is a program organization unit which provides values for its outputs and internal variable s according to the algorithms defined in its function block type description when executed as a specific instance All values of the outputs and internal variables of a specific function block instance are maintained from one invocation of the function block to the next Therefore multiple calls of the same function block instance with the same arguments values of input parameters do not necessarily yield the same output value s Each function block instance is graphically display
94. ut variable 1 as a Y2_PC REAL Manipulated variable Output variable 2 as a Y3_PC REAL Manipulated variable Output variable 3 as a ERR REAL System Deviation 66 00 UC3_VAC Table 2 PARA_UC3 Element Data Type Meaning SP_SPCV BOOL Setpoint setpoint command variable PI Controller YMAX REAL Upper limit manipulated variable YMIN REAL Lower limit manipulated variable GAIN REAL Controller gain PROP REAL Proportional value PREF REAL Proportional value reference Tl TIME Reset time 1 Sequence Xii REAL 1 Abcissa value Y1_1 REAL 1 Ordinate value X2_1 REAL 2 Abcissa value Y2_1 REAL 2 Ordinate value 2 Sequence X1_2 REAL 1 Abcissa value Y1_2 REAL 1 Ordinate value X2_2 REAL 2 Abcissa value Y2 2 REAL 2 Ordinate value 3 Sequence X1_3 REAL 1 Abcissa value Y1_3 REAL 1 Ordinate value X2_3 REAL 2 Abcissa value Y2 3 REAL 2 Ordinate value 00 67 UC3_VAC 3 1 Detailed description EFB Structure A block diagram representation of the UC3_VAC complex function block is shown in Figure 1 It is made up of the following basic function blocks m SW_VAC Summer winter compensation see page 54 m PIVAC Basic PI controller for HVAC applications see page 45 m SEQ VAC Output Sequence scaling module see page 49 Please refer to the respective individual basic function block description for detail

Concept Functionblocks for Heating, Ventilation & Air Condition

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Concept Functionblocks for Heating, Ventilation &amp; Air Condition

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Concept Functionblocks for Heating, Ventilation & Air Condition