Chapter 3 - AutomationDirect
Contents
1. Mode Switch Functions The mode switch on the DLOS PLC provides positions for enabling and disabling program changes in the CPU Unless the mode switch is in the TERM position RUN and STOP mode changes will not be allowed by any interface device handheld programmer DirectSOFT 5 programing package or operator interface Programs may be viewed or monitored but no changes may be made If the switch is in the TERM position and no program password is in effect all operating modes as well as program access will be allowed through the connected programming or monitoring device NOTE If the DLO5 is switched to the RUN Mode without a program in the PLC the PLC will produce a FATAL ERROR which can be cleared by cycling power to the PLC 3 6 DLO5 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation nS Changing Modes in the DLOS PLC Modeswitch Position CPU Action CPU is forced into the RUN mode if no errors are RUN Run Program encountered No changes are allowed by the attached programming monitoring device PROGRAM and the TEST modes are available Mode and TERM Terminal RUN program changes are allowed by the programming monitoring device STOP CPU is forced into the STOP mode No changes are allowed by the programming monitoring device There are two ways to change the CPU mode You can use the CPU mode switch to select the o2. structured program similar to a flowchart Each program 1 3 4 5 Stage denotes a program segment When the program segment or Stage is active the logic within that segment Ladder Representation is executed If the Stage is off or inactive the logic isnot 3 executed and the CPU skips to the next active Stage See S0000 Wait for Start Chapter 7 for a more detailed description of RLLPLUS Start y st programming kd amp 500 Each Stage also has a discrete status bit that can be used as IMP SG an input to indicate whether the Stage 1s active or 0001 Check for a Part inactive If the Stage is active then the status bit is on If Part oo 5 Present 2 the Stage is inactive then the status bit is off This status JMP bit can also be turned on or off by other instructions a such as the SET or RESET instructions This allows you Present JMP to easily control stages throughout the program x SG S0002 Clamp the part ser Part 400 Locked s3 JMP Lo Special Relays SP Data Type Special relays are discrete memory locations with pre defined functionality There are many different t f ial rel yee ae ty y ypes of special relays our For example some aid in program development others provide system operating status information etc Appendix D provides a complete listing of the special relays In this example control relay C10 will energize for 50 ms and SP4 1 second clock
3. CPU SPECIFICATIONS AND HAPTER OPERATION In This Chapter IMMECOUCHON twee rd EA MERE eS 3 2 CPU Specifications Sieh can ene Sheet ee o tree Gewese ees 3 3 CPU Hardware SQUID 2 01 0se ee Stiedneededenteeeso neue es 3 4 CPU ISCIANON sc EE DA RO 3 11 WO Response TIME oia RIOR ARENAS 3 15 CPU Scan Time Considerations co 0542205 sree aneetankeeeas 3 18 Memory Map aceras ti tonr tedecan baae es 3 22 DLOS System V MEMON wie Gh vo anio kG eer aos ee BS 3 26 DIOS ANASES cir aia A AR Rees 3 29 IRPUE Bt Map e errar yr rra eee en 3 30 Y Output BI Map on ca bewtipeageneensenedeedeeereeeeee 3 30 Control Relay Bit Map sa ccsoes Ke be need drase eee ees 3 31 Stage Control Status Bit Map sr care AA 3 32 Timer Status BIE Map 0 00000009 eee merest ak we e ei 3 32 Counter Status Bit Map os cas tecnctasey bade rip 3 33 Chapter 3 CPU Specifications and Operation Introduction The Central Processing Unit CPU is the heart of the Micro PLC Almost all PLC operations are controlled by the CPU so it is important that it is set up correctly This chapter provides the information needed to understand e Steps required to set up the CPU e Operation of ladder programs e Organization of Variable Memory To Programming Device or Operator Interface DLO5 y PLC CPU 2 Comm f Ports ry Main Power Supply 4 Input Circuit Output Circuit Power Y i
4. de energize for 50 ms because SP5 is a pre defined relay that will SP5 100 ms clock be on for 50 ms and off for 50 ms SP6 50 ms clock DLO5 Micro PLC User Manual 6th Edition Rev C 3 25 Chapter 3 CPU Specifications and Operation DLO5 System V memory System Parameters and Default Data Locations V Data Type The DLO5 PLCs reserve several V memory locations for storing system parameters or certain System V memory Description of Contents types of system data These memory locations store things like the error codes High Speed T O data and other types of system setup information Default Values Ranges V2320 V2377 The default location for multiple preset values for the High Speed Counter N A V7620 V7627 Locations for DV 1000 operator interface parameters V7620 Sets the V memory location that contains the value VO V2377 V7621 Sets the V memory location that contains the message VO V2377 V7622 Sets the total number 1 16 of V memory locations to be displayed 1 16 V7623 Sets the V memory location containing the numbers to be displayed VO V2377 V7624 Sets the V memory location containing the character code to be displayed VO V2377 V7625 Contains the function number that can be assigned to each key V memory location for X Y or C points used V7626 Power up operational mode 0 1 2 12 3 V7627 Change pres
5. lt DirectSOFT 5 to enter a password The following T diagram shows how you can enter a password with the Handheld Programmer DirectSOFT D2 HPP Select AUX 81 l B s E MN E PASSWORD 00000000 CLR CLR Enter the new 8 digit password siod t x PASSWORD XXXXXXXX Press CLR to clear the display There are three ways to lock the CPU once the password has been entered 1 If the CPU power is disconnected the CPU will be automatically locked against access 2 If you enter the password with DirectSOFT 5 the CPU will be automatically locked against access when you exit DirectSOFT 5 3 Use AUX 83 to lock the CPU When you use DirectSOFT 5 you will be prompted for a password if the CPU has been locked If you use the Handheld Programmer you have to use AUX 82 to unlock the CPU Once you enter AUX 82 you will be prompted to enter the password 3 10 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation CPU Operation Achieving the proper control for your equipment or process requires a good understanding of how DL05 CPUs control all aspects of system operation There are four main areas to understand before you create your application program e CPU Operating System the CPU manages all aspects of system control A quick overview of all the steps is provided in the next sectio
6. 100 00 EN eG SS a Are 112 111 110 107 106 105 104 V40504 3 30 DLO5 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation Control Relay Bit Map This table provides a listing of the individual control relays associated with each V memory address bit DLO5 Control Relays C Address V40600 V40601 V40602 V40603 V40604 V40605 V40606 V40607 V40610 V40611 V40612 V40613 V40614 V40615 V40616 V40617 V40620 V40621 V40622 V40623 V40624 V40625 V40626 V40627 V40630 V40631 V40632 V40633 V40634 V40635 V40636 V40637 DL05 Micro PLC User Manual 6th Edition Rev C 3 3 1 Chapter 3 CPU Specifications and Operation i Q x x O CRE _ e R R I Stage Control Status Bit Map This table provides a listing of individual Stage control bits associated with each V memory address bit DLO5 Stage S Control Bits a Peale ies Address 012 011 010 007 006 005 41000 032 031 030 027 026 025 41001 052 051 050 047 046 045 41002 072 071 070 067 066 065 41003 112 111 110 107 106 105 V41004 1
7. Clear All Ladders 62 Beeper On Off AUX 3 V Memory Operations 65 Run Self Diagnostics 31 Clear V Memory AUX 7 EEPROM Operations AUX 4 1 0 Configuration 71 Copy CPU memory to HPP EEPROM 41 Show 1 0 Configuration 72 Write HPP EEPROM to CPU AUX 5 CPU Configuration 73 Compare CPU to HPP EEPROM 51 Modify Program Name 74 Blank Check HPP EEPROM 53 Display Scan Time 75 Erase HPP EEPROM 54 Initialize Scratchpad 76 Show EEPROM Type CPU and HPP 55 Set Watchdog Timer AUX 8 Password Operations 56 Set Communication Port 2 81 Modify Password 57 Set Retentive Ranges 82 Unlock CPU 58 Test Operations 83 Lock CPU 59 Override Setup Clearing an Existing Program Before you enter a new program be sure to always clear ladder memory You can use AUX Function 24 to clear the complete program You can also use other AUX functions to clear other memory areas e AUX 23 Clear Ladder Range e AUX 24 Clear all Ladders e AUX 31 Clear V Memory Initializing System Memory The DLO5 Micro PLC maintain system parameters in a memory area often referred to as the scratchpad In some cases you may make changes to the system setup that will be stored in system memory For example if you specify a range of Control Relays CRs as retentive these changes are stored in system memory AUX 54 resets the system memory to the default values 3 8 DLO5 Micro PLC U
8. Input 8 Discrete Inputs Commons 6 Discrete Outputs Commons NOTE The High Speed 1 0 function HSIO consists of dedicated but configurable hardware in the DLOB It is not considered part of the CPU because it does not execute the ladder program For more on HSIO operation see Appendix E DLO5 CPU Features The DLO5 Micro PLC which has 6K words of memory comprised of 2K of ladder memory and 4K words of V memory data registers Program storage is in the FLASH memory which is a part of the CPU board in the PLC In addition there is RAM with the CPU which will store system parameters V memory and other data which is not in the application program The RAM is backed up by a super capacitor storing the data for several hours in the event of a power outage The capacitor automatically charges during powered operation of the PLC The DLOS supports fixed I O which includes eight discrete input points and six output points If more than the fourteen fixed I O points are needed select an I O module for your application from the DL05 06 Option Modules User Manual This module will plug into the expansion slot Over 120 different instructions are available for program development as well as extensive internal diagnostics that can be monitored from the application program or from an operator interface Chapters 5 6 and 7 provide detailed descriptions of the instructions The DLOS provides two built in RS232C communication ports so you can e
9. Scan Time Considerations The scan time covers all the cyclical tasks that are ED Power up performed by the operating system You can use DirectSOFT 5 or the Handheld Programmer to display the minimum maximum and current scan times that Initialize hardware have occurred since the previous Program Mode to Run Hidra ON Mode transition This information can be very important configuration when evaluating the performance of a system As we ve shown previously there are several segments that make up the scan cycle Each of these segments requires a certain amount of time to complete Of all the segments the Service peripheral following are the most important Update input e Input Update Update Special Relays e Peripheral Service PGM P Mode e Program Execution e Output Update RUNE Execute program e Timed Interrupt Execution The only one you really have the most control over is the Update output amount of time it takes to execute the application program This is because different instructions take Do diagnostics different amounts of time to execute So if you think you need a faster scan then you can try to choose faster YES instructions o NO Your choice of I O type and peripheral devices can also Report error set flag affect the scan time However these things are usually register turn on LED dictated by the application NO The followi
10. V memory data tal bi Variable memory called V memory octal MSB peca LSB stores data for the ladder program Np Osa L OO PIE 2 RA ON A R KOE A and for configuration settings V memory locations and V memory addresses are the same thing and are numbered in octal For example V2073 is a valid location while V1983 is not valid 9 and 8 are not valid octal digits ES Each V memory location is one data word wide meaning 16 bits For configuration registers our manuals will show each bit of a V memory word The least significant bit LSB will be on the right and the most significant bit MSB on the left We use the word significant referring to the relative binary weighting of the bits V memory data is 16 bit binary but we rarely program the data registers one bit at a time We use instructions or viewing tools that let us work with decimal octal and hexadecimal numbers All these are converted and stored as binary for us A frequently asked question is How do I tell if a number is octal BCD or hex The answer is that we usually cannot tell just by looking at the data but it does not really matter What matters is the source or mechanism which writes data into a V memory location and the thing which later reads it must both use the same data type i e octal hex binary or whatever The V memory location is just a storage box that s al
11. evaluates each instruction in the application program during this segment of the scan cycle The instructions define the relationship between the input conditions and the desired output response The CPU uses the output image register area to store the status of the desired action for the outputs Output image register locations are designated with a Y followed by a memory location The actual outputs are updated during the write outputs segment of the scan cycle There are immediate output instructions available that will update the output points immediately instead of waiting until the write output segment A complete list of the Immediate instructions is provided in Chapter 5 The internal control relays C the stages S and the variable memory V are also updated in this segment You may recall that you can force various types of points in the system This was discussed earlier in this chapter If any I O points or memory data have been forced the output image register also contains this information 3 14 DL05 Micro PLC User Manual 6th Edition Rev C Normal Run mode scan YY Read Inputs y Service Peripherals y Update Special Relays y Solve the Application Program y Write Outputs Y Diagnostics A Chapter 3 CPU Specifications and Operation Write Outputs Once the application program has solved the instruction logic and constructed the o
12. tat Decimal 1 23 4 5 6 7 8 Octal means simply counting in groups of eight things at a time In the figure to the right there are eight circles The quantity in decimal is 8 but in Octal 1234567 10 octal it is 10 8 and 9 are not valid in octal In E octal 10 means 1 group of 8 plus O no individuals In the figure below we have two groups of eight circles Counting in octal we have 20 items meaning 2 groups of eight plus 0 individuals Dont say twenty say two zero octal This makes a clear distinction between number systems Decimal 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Octal 123 4 5 6 7 10 11 12 13 1415 16 17 20 After counting PLC resources it is time to access PLC resources there is a difference The CPU instruction set accesses resources of the PLC using octal addresses Octal addresses are the same as octal quantities except they start counting at zero The number zero is significant to a computer so we dont skip it X 0 123 4 5 6 7 Our circles are in an array of square containers to the right To access a resource our PLC instruction X will address its location using the octal references 0 shown If these were counters CT14 would 1X access the black circle location 2X 3 20 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation V memory V memory address
13. understand how the CPU updates the I O points handles forcing operations and solves the application program The remaining segments are not that important for most applications You can use DirectSOFT 5 or the D2 HPP Handheld Programmer to place the CPU in Run Mode You can also edit the program during Run Mode The Run Mode Edits are not bumpless to the outputs Instead the CPU maintains the outputs in their last state while it accepts the new program information If an error is found in the new program then the CPU will turn all the outputs off and enter the Program Mode This feature is discussed in more detail in Chapter 9 Normal Run mode scan YN Read Inputs Y Service Peripherals Y Update Special Relays Y Solve the Application Program Y Write Outputs Y Diagnostics VJ WARNING Only authorized personnel fully familiar with all aspects of the application should make changes to the program Changes during Run Mode become effective immediately Make sure you thoroughly consider the impact of any changes to minimize the risk of personal injury or damage to equipment Chapter 3 CPU Specifications and Operation Read Inputs The CPU reads the status of all inputs then stores it in the image register Input image register locations are designated with an X followed by a memory location Image register data is used by the CPU when it solv
14. value of a corresponding timer K30 When input XO turns on timer T1 will start When the timer reaches the preset of 3 seconds K30 timer status contact T1 turns on When T1 turns on output Y12 turns on Turning off X0 resets the timer T1 Y12 our DLO5 Micro PLC User Manual 6th Edition Rev C 3 23 Chapter 3 CPU Specifications and Operation Timer Current Values V Data Type As mentioned earlier some information is automatically stored in V memory This is true for the current values associated with timers For example VO holds the current value for Timer 0 V1 holds the current value for Timer 1 etc The primary reason for this is programming flexibility The example shows how you can use relational contacts to monitor several time intervals from a single timer Counters and Counter Status Bits CT Data type Counter status bits that reflect the relationship between the current value and the preset value of a specified counter The counter status bit will be on when the current value is equal to or greater than the preset value of a corresponding counter Each time contact XO transitions from off to on the counter increments by one If X1 comes on the counter is reset to zero When the counter reaches the preset of 10 counts K of 10 counter status contact CT3 turns on When CT3 turns on output Y2 turns on Counter Current Values V Data Type Just like the timers the c
15. 0 V41147 128 CNT CTO K10 Current Values None V1000 V1177 128 V1000 K100 2 Counter Status Bits CTO CT177 V41140 V41147 128 CTO Data Words See Appendix F None V1200 V7377 3968 None specific used with many instructions Data Words Non volatile See Appendix F V7400 V7977 None specific used with many instructions May be non volatile if MOV inst is used Data can be rewritten to EEPROM at least 100 000 times before it fails Stages S0 377 V41000 V41017 SG SPO 4 H S001 System parameters None V7600 V7777 3 28 DL05 Micro PLC User Manual 6th Edition Rev C None specific used for various purposes NOTE The DLO5 has 8 discrete inputs and 6 discrete outputs which are standard The number of inputs and or outputs can be increased by adding one of the available option modules Refer to either the DL05 06 Option Modules User Manual DO OPTIONS M our catalog or our website Chapter 3 CPU Specifications and Operation DLO5 Aliases An alias is an alternate way of referring to certain memory types such as timer counter current values V memory locations for I O points etc which simplifies understanding the memory address The use of the alias is optional but some users may find the alias to be helpful when developing a program The table below shows how the aliases c
16. 00 23 V7771 Contains the day of week on optional Memory Cartridge Mon Tues Wed etc V7772 Contains the numerical day of month on optional Memory Cartridge 01 02 etc V7773 Contains the numerical month on optional Memory Cartridge 01 to 12 V7774 Contains the year on optional Memory Cartridge 00 to 99 V7775 Scan stores the current scan time milliseconds V7776 Scan stores the minimum scan time that has occurred since the last Program Mode to Run Mode transition milliseconds V7777 Scan stores the maximum scan time that has occurred since the last Program Mode to Run Mode transition milliseconds DL05 Micro PLC User Manual 6th Edition Rev C 3 27 Chapter 3 CPU Specifications and Operation DL05 Memory Map Table Memory Type Discrete Memory Reference octal Word Memory Reference octal Decimal Symbol Input Points See note X0 X377 V40400 V40417 256 X0 q E Output Points See note YO Y377 V40500 V40517 256 YO c0 C777 V40600 V40637 512 co co JH gt SPO SP777 V41200 V41237 512 SPO q E TO T177 V41100 V41107 128 TO K100 _ TMR Timer Current Values None VO V177 128 VO K100 gt Timer Status Bits 10 1177 V41100 V41107 128 TO 4k CTO C1177 V4114
17. 151 150 147 146 145 V41146 172 171 170 167 166 165 V41147 DL05 Micro PLC User Manual 6th Edition Rev C 3 33
18. 32 131 130 127 126 125 V41005 152 151 150 147 146 145 41006 172 171 170 167 166 165 41007 212 211 210 207 206 205 V41010 232 231 230 227 226 225 V41011 252 251 250 247 246 245 V41012 272 271 270 267 266 265 V41013 312 311 310 307 306 305 V41014 332 331 330 327 326 325 V41015 352 351 350 347 346 345 V41016 372 371 370 367 366 365 V41017 Timer Status Bit Map This table provides a listing of individual timer contacts associated with each V memory address bit DLO5 Timer T Contacts 9 3 7 6 5 Address 011 010 007 006 V41100 031 030 027 026 V41101 051 050 047 046 V41102 071 070 067 066 V41103 111 110 107 106 V41104 131 130 127 126 V41105 151 150 147 146 V41106 171 170 167 166 V41107 3 32 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation SS Counter Status Bit Map This table provides a listing of individual counter contacts associated with each V memory address bit DLO5 Counter CT Contacts Doray eos putes 012 011 010 007 006 005 V41140 032 031 030 027 026 025 V41141 052 051 050 047 046 045 V41142 072 071 070 067 066 065 V41143 112 111 110 107 106 105 V41144 132 131 130 127 126 125 V41145 152
19. 60 filter to 0 msec for XO X1 X2 and X3 Of these four things the Immediate I O instructions are probably the most important and most useful The following example shows how an immediate input instruction and immediate output instruction would affect the response time Scan Solve Solve Solve Solve Scan Program Program Program Program Normal Read NX write Normal Read Input Output Write Input Immediate Immediate Outputs _ Field Input Input _ Off On Delay Output Off On Delay I e 1 0 Response Time In this case you can calculate the response time by simply adding the following items Input Delay Instruction Execution Time Output Delay Response Time The instruction execution time would be calculated by adding the time for the immediate input instruction the immediate output instruction and any other instructions in between the two NOTE Even though the immediate instruction reads the most current status from 1 0 it only uses the results to solve that one instruction It does not use the new status to update the image register Therefore any regular instructions that follow will still use the image register values Any immediate instructions that follow will access the 1 0 again to update the status DL05 Micro PLC User Manual 6th Edition Rev C 3 17 Chapter 3 CPU Specifications and Operation CPU
20. N C102 2 3 US LD K50 42 7 us STRN C103 2 3 us OUT V2006 16 6 us STR X5 2 0 us ANDN X10 1 6 us OUT Y3 6 8 us END 24 0 us SUBTOTAL 174 2 us Overhead DLO5 Minimum Maximum TOTAL TIME Program execution time Overhead x 1 1 x0 x1 j Yo Y AUT co C100 Te K10 c101 OUT v2002 C102 D K50 C103 OUT v2006 X5 x10 Y3 OUT END The program above takes only 174 2 ps to execute during each scan The DLOS spends 0 1 ms on internal timed interrupt management for every 1 0 ms of instruction time The total scan time is calculated by adding the program execution time to the overhead shown above and multiplying the result ms by 1 1 Overhead includes all other housekeeping and diagnostic tasks The scan time will vary slightly from one scan to the next because of fluctuation in overhead tasks Program Control Instructions the DLOS PLCs have an interrupt routine feature that changes the way a program executes Since this instruction interrupts normal program flow it will have an effect on the program execution time For example a timed interrupt routine with a 10 0 ms period interrupts the main program execution before the END statement every 10 0 ms so the CPU can execute the interrupt routine Chapter 5 provides detailed information on interrupts DLO5 Micro PLC User Manual 6th Edition Rev C 3 19 Chapter 3 CPU Specifications and Operation PLC Numbering Systems me
21. an be used DLO5 Aliases Address Start VO Alias Start Example VO is the timer accumulator value for timer 0 therefore its alias is TAO TA1 is the alias for V1 etc V1000 V1000 is the counter accumulator value for counter 0 therefore its alias is CTAO CTA1 is the alias for V1001 etc V40400 V40400 is the word memory reference for discrete bits XO through X17 therefore its alias is VXO V40401 is the word its alias is VX20 memory reference for discrete bits X20 through X37 therefore V40500 V40500 is the word memory reference for discrete bits YO through Y17 therefore its alias is VYO V40501 is the word its alias is VY20 memory reference for discrete bits Y20 through Y37 therefore V40600 V40600 is the word memory reference for discrete bits CO through C17 therefore its alias is VCO V40601 is the word its alias is VC20 memory reference for discrete bits C20 through C37 therefore V41000 V41000 is the word memory reference for discrete bits SO through S17 therefore its alias is VSO V41001 is the word its alias is VS20 memory reference for discrete bits S20 through S37 therefore V41100 V41100 is the word memory reference for discrete bits TO through T17 therefore its alias is VTO V41101 is the word its alias is VT20 memory reference for discrete bits T20 through T37 therefore V41140 V41140 is the word memory reference for disc
22. ardware Initialize various memory based on retentive configuration Update input Service peripheral Update Special Relays RUN PGM Moer gt Execute program Update output ___ Do diagnostics YES lt 0 NO Report error set flag register turn on LED rs gt error YES Force CPU into PGM mode Chapter 3 CPU Specifications and Operation 3 12 DL05 Micro PLC User Manual 6th Edition Rev C Program Mode In Program Mode the CPU does not execute the application program or update the output points The primary use for Program Mode is to enter or change an application program You also use program mode to set up the CPU parameters such as HSIO features retentive memory areas etc You can use a programming device such as a PC with DirectSOFT 5 Programming Software or the D2 HPP Handheld programmer to place the CPU in Program Mode Run Mode In Run Mode the CPU executes the application program and updates the I O system You can perform many operations during Run Mode Some of these include e Monitor and change I O point status e Update timer counter preset values e Update Variable memory locations Run Mode operation can be divided into several key areas For the vast majority of applications some of these execution segments are more important than others For example you need to
23. asily connect a handheld programmer operator interface or a personal computer without needing any additional hardware 3 2 DLO5 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation CPU Specifications Specifications Feature DLOS Total Program memory words 6K Ladder memory words 2048 Total V memory words 4096 User V memory words 3968 Non volatile V Memory words 128 Contact execution boolean 2 0us Typical scan 1k boolean 2 3 2MS RLL Ladder Style Programming Yes RLL and RLLPLUS Programming Yes Run Time Edits Yes Supports Overrides Yes Scan Variable fixed Handheld programmer Yes DirectSOFT 5 programming for Windows Yes Built in communication ports RS232C Yes FLASH Memory Standard on CPU Local Discrete 1 0 points available 14 Local Analog input output channels maximum None High Speed 1 0 quad pulse out interrupt pulse catch etc Yes 2 1 0 Point Density 8 inputs 6 outputs Number of instructions available see Chapter 5 for details 129 Control relays 512 Special relays system defined 512 Stages in RLLPLUS 256 128 128 Yes Yes Yes Yes Integer Drum Sequencer Instruction Yes Time of Day Clock Calendar Only with the opti
24. ctSOFT 5 Programming Software User Manual provides a description of the menus and keystrokes required to perform the setup procedures DL05 Micro PLC User Manual 6th Edition Rev C 3 5 Chapter 3 CPU Specifications and Operation Mode Switch L O n U U INPUT OUTPUT XO X1 X2 X3 X4 X5 X6 X7 YO Y1 Y2 Y3 Y4 Y5 9333993999939 my m Direct Status Ie 05 a m Indicators a AA 95 240V 30VA 50 60 He ACI Ac co xi yl xe c2 yt I Ya Ys eae ee SPT E xo x7 Input vo vs ouma E ES e ES EEES EEES EE el mm Ls Sl Status Indicators The status indicator LEDs on the CPU front panels have specific functions which can help in programming and troubleshooting Indicator Meaning PWR Power good Power failure CPU is in Run Mode RUN CPU is in Stop or program Mode CPU is in upgrade Mode CPU self diagnostics error CPU self diagnostics good Data is being transmitted by the CPU Port 1 No data is being transmitted by the CPU Port 1 Data is being received by the CPU Port 1 No data is being received by the CPU Port 1 Data is being transmitted by the CPU Port 2 No data is being transmitted by the CPU Port 2 Data is being received by the CPU Port 2 No data is being received by the CPU Port 2
25. es the application program scan time is measured in milliseconds If you have an application that cannot wait until the next I O update you can use Immediate Instructions These do not use the status of the input image register to solve the application program The Immediate instructions immediately read the input status directly from the I O modules However this lengthens the program scan since the CPU has to read the I O point status again A complete list of the Immediate instructions is included in Chapter 5 Of course an input may change after the CPU has just read the inputs Generally the CPU 3 Service Peripherals and Force I O After the CPU reads the inputs from the input modules it reads any attached peripheral devices This is primarily a communications service for any attached devices For example it would read a programming device to see if any input output or other memory type status needs to be modified There are two basic types of forcing available with the DLOS CPUs e Forcing from a peripheral not a permanent force good only for one scan e Bit Override holds the I O point or other bit in the current state Valid bits are X Y C T CT and S These memory types are discussed in more detail later in this chapter Regular Forcing This type of forcing can temporarily change the status of a discrete bit For example you may want to force an input on even though it is really off This allows you to cha
26. et value 0000 to 9999 V7630 Starting location for the multi step presets for channel 1 The default value is 2320 which indicates the first value should be obtained from V2320 Since there are 24 presets available the default range is V2320 V2377 You can change the starting point if necessary Default V2320 Range VO V2320 V7631 V7632 Reserved N A Sets the desired function code for the high speed counter interrupt pulse catch pulse train and input filter Location can also be used to set the power up in Run Mode option Default 0060 Lower Byte Range Range 10 Counter 20 Quadrature 30 Pulse Out 40 Interrupt 50 Pulse Catch 60 Filtered discrete In Upper Byte Range Bits 8 12 14 15 Unused Bit 13 Power up in RUN if Mode Switch is in TERM position Setup Registers for High Speed 1 0 functions Default 1006 Pulse Direction Default 0000 V7640 V7646 Reserved N A V7647 Timed Interrupt Default 0000 Range 0003 03E7h 3 9999ms V7650 V7654 Reserved N A V7655 Port 2 Setup for the protocol time out and the response delay time Default OOEO V7656 3 26 Port 2 Setup for the station number baud rate STOP bit and parity DLO5 Micro PLC User Manual 6th Edition Rev C Default 8501 System V memory Chapter 3 CPU Specifications and Operation Description of Contents Defa
27. from the application program or from the I O update until the bit override is removed The following diagram shows a brief overview of the bit override feature Notice the CPU does not update the Image Register when bit override is enabled DLO5 Micro PLC User Manual 6th Edition Rev C 3 13 Chapter 3 CPU Specifications and Operation Bit Override OFF a A Input Update ea Force from Programmer Result of Program Solution ee X128 X2 X1 XO OFF ON ON OFF inpy gt Medate Y128 Y2 Y1 YO OFF ON ON OFF C377 C2 cl CO Force from Programmer OFF ON OFF OFF Image Register example Update Special Relays and Special Registers There are dedicated V memory locations that contain Special Relays and other dedicated register information This portion of the execution cycle makes sure these locations get updated on every scan Also there are several different Special Relays such as diagnostic relays etc that are also updated during this segment Solve Application Program Result Ok Pr gram Solutio Bit Override ON WARNING Only authorized personnel fully familiar with all aspects of the application should make changes to the program Make sure you thoroughly consider the impact of any changes to minimize the risk of personal injury or damage to equipment The CPU
28. ften need this full range for sensor data etc Hexadecimal is just a convenient way for humans to view full binary data Hexadecimal number A 7 F 4 V memory storage 1 0 1 0 0 1 1 1 111 11 0 1 0 0 DL05 Micro PLC User Manual 6th Edition Rev C 3 2 1 Chapter 3 CPU Specifications and Operation Octal Numbering System Discrete and Word Locations Memory Map With any PLC system you generally have many different types of information to process This includes input device status output device status various timing elements parts counts etc It is important to understand how the system represents and stores the various types of data For example you need to know how the system identifies input points output points data words etc The following paragraphs discuss the various memory types used in DL05 Micro PLCs A memory map overview for the CPU follows the memory descriptions All memory locations and resources are numbered in Octal base 8 For example the diagram shows how the octal numbering system works for the discrete input points Notice the octal system does not contain any numbers with the digits 8 or 9 XO X1 X2 X3 X4 X5 XE X7 As you examine the different memory types you ll Discrete On or Off 1 bit notice two types of memory in the DLOS d
29. he TERM position Failure to adhere to this warning greatly increases the risk of unexpected equipment startup The mode which the CPU will power up in is also determined by the state of B7633 13 If the bit is set and the Mode Switch is in the TERM position then the CPU will power up in the state it was in at power down DL05 Micro PLC User Manual 6th Edition Rev C 3 7 Chapter 3 CPU Specifications and Operation Auxiliary Functions Many CPU setup tasks involve the use of Auxiliary AUX Functions The AUX Functions perform many different operations ranging from clearing ladder memory displaying the scan time copying programs to EEPROM in the handheld programmer etc They are divided into categories that affect different system parameters Appendix A provides a description of the AUX functions You can access the AUX Functions from DirectSOFT 5 or from the D2 HPP Handheld Programmer The manuals for those products provide step by step procedures for accessing the AUX Functions Some of these AUX Functions are designed specifically for the Handheld Programmer setup so they will not be needed or available with the DirectSOFT 5 package The following table shows a list of the Auxiliary functions for the Handheld Programmer AUX 2 RLL Operations 5B HSIO Configuration 21 Check Program 5D Scan Control Setup 22 Change Reference AUX 6 Handheld Programmer Configuration 23 Clear Ladder Range 61 Show Revision Numbers 24
30. iscrete XO and word memory Discrete memory is one bit that can be either a 1 or a 0 Word memory is referred to as V memory variable and is a 16 bit location normally used to manipulate data numbers store data numbers etc Word Locations 16 bits Some information is automatically stored in 0 11010000001 0 0 1 0 1 V memory For example the timer current values are stored in V memory V memory Locations for Discrete Memory Areas The discrete memory area is for inputs outputs control relays special relays stages timer status bits and counter status bits However you can also access the bit data types as a V memory word Each V memory location contains 16 consecutive discrete locations For example the following diagram shows how the X input points are mapped into V memory locations 8 Discrete X Input Points Bit 15 14 13 12 11 10 9 8 zi ef 5 44 3 2 1 0 V40400 These discrete memory areas and their corresponding V memory ranges are listed in the memory area table for DLOS Micro PLCs on the following pages 3 22 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation Input Points X Data Type The discrete input points are n
31. l It does not convert or move the data on its own Binary Coded Decimal Numbers Since humans naturally count in decimal 10 fingers 10 toes we prefer v memory storage 0 1 0 0 1 0 0 1 PEEN CECT to enter and view PLC data in decimal as well However computers are more efficient in using pure binary numbers A compromise solution between the two is Binary Coded Decimal BCD representation A BCD digit ranges from 0 to 9 and is stored as four binary bits a nibble This permits each V memory location to store four BCD digits with a range of decimal numbers from 0000 to 9999 BCD number 4 9 3 6 In a pure binary sense a 16 bit word can represent numbers from 0 to 65535 In storing BCD numbers the range is reduced to only 0 to 9999 Many math instructions use Binary Coded Decimal BCD data and DirectSOFT 5 and the handheld programmer allow us to enter and view data in BCD Hexadecimal Numbers Hexadecimal numbers are similar to BCD numbers except they utilize all possible binary values in each 4 bit digit They are base 16 numbers so we need 16 different digits To extend our decimal digits 0 through 9 we use A through F as shown Decimal 012 3 4 5 6 7 8 9 10 11 12 13 14 15 Hexadecimal 0123 45 67 89 ABCODE F A 4 digit hexadecimal number can represent all 65536 values in a V memory word The range is from 0000 to FFFF hex PLCs o
32. n e CPU Operating Modes The two primary modes of operation are Program Mode and Run Mode e CPU Timing The two important areas we discuss are the I O response time and the CPU scan time e CPU Memory Map DL05 CPUs offer a wide variety of resources such as timers counters inputs etc The memory map section shows the organization and availability of these data types Power up CPU Operating System At powerup the CPU initializes the internal electronic hardware Memory initialization starts with examining the retentive memory settings In general the content of retentive memory is preserved and non retentive memory is initialized to zero unless otherwise specified After the one time powerup tasks the CPU begins the cyclical scan activity The flowchart to the right shows how the tasks differ based on the CPU mode and the existence of any errors The scan time is defined as the average time around the task loop Note that the CPU is always reading the inputs even during program mode This allows programming tools to monitor input status at any time The outputs are only updated in Run mode In program mode they are in the off state Error detection has two levels Non fatal errors are reported but the CPU remains in its current mode If a fatal error occurs the CPU is forced into program mode and the outputs go off DL05 Micro PLC User Manual 6th Edition Rev C 3 1 1 Initialize h
33. nee If you are a new PLC user or are using AutomationDirect 1482 BCD PLCs for the first time please take a moment to study how ae 2 3 oo our PLCs use numbers You ll find that each PLC 7 961428 ASCII manufacturer has their own conventions on the use of 1001011011 hexadecimal numbers in their PLCs We want to take just a moment to 2 177 1011 familiarize you with how numbers are used in decimal A 72B AutomationDirect PLCs The information you learn here 300124 applies to all of our PLCs As any good computer does PLCs store and manipulate numbers in binary form just ones and zeros So why do we have to deal with numbers in so many different forms Numbers have meaning and some representations are more convenient than others for particular purposes Sometimes we use numbers to represent a size or amount of something Other numbers refer to locations or addresses or to time In science we attach engineering units to numbers to give a particular meaning see Appendix I for numbering system details PLC Resources PLCs offer a fixed amount of resources depending on the model and configuration We use the word resources to include variable memory V memory I O points timers counters etc Most modular PLCs allow you to add I O points in groups of eight In fact all the resources of our PLCs are counted in octal It s easier for computers to count in groups of eight than ten because eight is an even power of 2 E
34. ng paragraphs provide some general Fatal error information on how much time some of the segments can require Force CPU into q PG M mode Reading Inputs The time required during each scan to read the input status is 40 ps Don t confuse this with the I O response time that was discussed earlier Writing Outputs The time required to write the output status is 629 us Don t confuse this with the I O response time that was discussed earlier 3 18 DL05 Micro PLC User Manual 6th Edition Rev C Application Program Execution Chapter 3 CPU Specifications and Operation The CPU processes the program from address 0 to the END instruction The CPU executes the program left to right and top to bottom As each rung is evaluated the appropriate image register or memory location is updated The time required to solve the application program depends on the type and number of instructions used and the amount of execution overhead Just add the execution times for all the instructions in your program to determine to total ES execution time Appendix C provides a complete list of the instruction execution times for the DLOS Micro PLC For example the execution time for running the program shown below is calculated as follows Instruction Time STR X0 2 0 us OR CO 1 6 us ANDN X1 1 6 us OUT YO 6 8 us STRN C100 2 3 us LD K10 42 7 us STRN C101 2 3 US OUT V2002 16 6 us STR
35. nge the point status that was stored in the image register This value will be valid until the image register location is written to during the next scan This is primarily useful during testing situations when you need to force a bit on to trigger another event Bit Override Bit override can be enabled on a point by point basis by using AUX 59 from the Handheld Programmer or by using the Data View option within DirectSOFT 5 Bit override basically disables any changes to the discrete point by the CPU For example if you enable bit override for X1 and X1 is off at the time then the CPU will not change the state of X1 This means that even if X1 comes on the CPU will not acknowledge the change So if you used X1 in the program it would always be evaluated as off in this case Of course if X1 was on when the bit override was enabled then X1 would always be evaluated as on There is an advantage available when you use the bit override feature The regular forcing is not disabled because the bit override is enabled For example if you enabled the Bit Override for YO and it was off at the time then the CPU would not change the state of YO However you can still use a programming device to change the status Now if you use the programming device to force YO on it will remain on and the CPU will not change the state of YO If you then force YO off the CPU will maintain YO as off The CPU will never update the point with the results
36. nse Time o In this case you can calculate the response time by simply adding the following items Input Delay Scan Time Output Delay Response Time Normal Maximum I O Response The I O response time is longest when the input changes just after the Read Inputs portion of the execution cycle In this case the new input status is not read until the following scan Scan Solve Solve Solve Solve Scan Program Program Program Program N Read Write Inputs Outputs Field Input CPU Reads CPU Writes rat A Inputs Outputs Off On Delay Output Off On Delay L m la 1 O Response Time The following diagram shows an example of the timing for this situation In this case you can calculate the response time by simply adding the following items Input Delay 2 x Scan Time Output Delay Response Time 3 16 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation Improving Response Time There are a few things you can do the help improve throughput e You can choose instructions with faster execution times e You can use immediate I O instructions which update the I O points during the program execution e You can use the HSIO Mode 50 Pulse Catch features designed to operate in high speed environments See Appendix E for details on using this feature e Change Mode
37. onal Memory Cartridge Internal diagnostics Yes Password security Yes System error log No User error log No Battery backup DLOS5 Micro PLC User Manual 6th Edition Rev C 3 3 No built in super cap Yes with memory cartridge Chapter 3 CPU Specifications and Operation CPU Hardware Setup Communication Port Pinout Diagrams Cables are available that allow you to quickly and easily connect a Handheld Programmer or a personal computer to the DLO5 PLCs However if you need to build your own cables use the pinout information shown below The DLO5 PLCs require an RJ 12 phone plug to fit the built in jacks The Micro PLC has two built in RS232C communication ports Port 1 is generally used for connecting to a D2 HPP a PC with DirectSOFT operator interface Modbus slave or a DirectNET slave The baud rate is fixed at 9600 baud Port 2 can be used to connect to a D2 HPP DirectSOFT operator interface Modbus master slave or a DirectNET master slave Port 2 has a range of speeds from 300 baud to 38 4K baud NOTE The 5V pins are rated at 220mA maximum primarily for use with some operator interface units Port 1 Pin Descriptions Port 2 Pin Descriptions 123456 1 OV Power connection GND 1 OV Power connection GND bid 2 5V Power connection 2 5V Power connection 3 RXD Receive Data RS232C 3 RXD Receive Data RS232C 4 TXD Tran
38. onnect the computer to either of the DLOS s programming ports For an engineering office environment typical during program development this is the preferred method of programming En Use cable part no D2 DSCBL The Handheld programmer is connected to the CPU with a handheld programmer cable This device can be used for maintaining existing installations or making small program changes whenever a PC is not available The handheld programmer is shipped with a cable which is approximately 6 5 feet 200 cm long cable comes with HPP D For replacement cable use part DV 1000CBL CPU Setup Information Even if you have years of experience using PLCs there are a few things you need to do before you can start entering programs This section includes some basic things such as changing the CPU mode but it also includes some things that you may never have to use Here s a brief list of the items that are discussed Selecting and Changing the CPU Modes e Using Auxiliary Functions e Clearing the program and other memory areas e How to initialize system memory e Setting retentive memory ranges The following paragraphs provide the setup information necessary to get the CPU ready for programming They include setup instructions for either type of programming device you are using The D2 HPP Handheld Programmer Manual provides the Handheld keystrokes required to perform all of these operations The Dire
39. oted by an X data X y type There are 8 discrete input points and 256 our discrete input addresses available with DLO5 CPUs In this example the output point YO will be turned on when input XO energizes ES Output Points Y Data Type The discrete output points are noted by a Y data xi v type There are 6 discrete outputs and 256 discrete our output addresses available with DLOS CPUs In this example output point Y1 will be turned on when input X1 energizes Control Relays C Data Type Control relays are discrete bits normally used to SE s control the user program The control relays do our not represent a real world device that is they cannot be physically tied to switches output coils etc They are internal to the CPU Because of this control relays can be programmed as discrete inputs or discrete outputs These locations are used our in programming the discrete memory locations C or the corresponding word location which contains 16 consecutive discrete locations C5 Y10 In this example memory location C5 will energize when input X6 turns on The second rung shows a simple example of how to use a control relay as an input Timers and Timer Status Bits T Data Type Timer status bits reflect the relationship between the current value and the preset value of a specified timer The timer status bit will be on when the current value is equal or greater than the preset XO TMR TI
40. ounter current values are also automatically stored in V memory For example V1000 holds the current value for Counter CT0 V1001 holds the current value for Counter CT1 etc The primary reason for this is programming flexibility The example shows how you can use relational contacts to monitor the counter values 3 24 DL05 Micro PLC User Manual 6th Edition Rev C TMR T 1 K1000 VI K30 Y2 gt OUT VI K50 Y3 gt OUT V1 K75 V1 K100 y4 gt lt OUT es CNT CT3 K10 X1 CT3 j Y2 OUT AO CNT CT3 K10 X1 V1003 K1 Y2 gt OUT V1003 K3 Y3 gt OUT V1003 K5 V1003 K8 y4 gt lt OUT Chapter 3 CPU Specifications and Operation Word Memory V Data Type Word memory is referred to as V memory variable and is a i 16 bit location normally used to manipulate data numbers LD store data numbers etc Some information is automatically aie stored in V memory For example the timer current values are stored in V memory The example shows how a four cree ES digit BCD constant is loaded into the accumulator and then stored in a V memory location Word Locations 16 bits 0 0 0 10 0 1 1 0 1 0 0 0 1 0 1 Stages S Data type Stages are used in RLLPLUS programs to create a I tae o
41. perating mode or you can place the mode switch in the TERM position and use a programming device to change operating modes With the switch in this position the CPU can be changed between Run and Program modes You can use either DirectSOFT 5 or the Handheld Programmer to change the CPU mode of operation With DirectSOFT 5 use the PLC menu option PLC gt Mode or use the Mode button located on the Online toolbar With the Handheld Programmer you use the MODE key D yd Ladies Ve Be GR gens ya Loh olas dos tp Sou Y Ps Cleat fis Wate Valor pocorn b JA ane ED tla SSS Se fo OOOO E TO J EI OMICIC C S A n anei 4 toni E OOOO E me s QOO E Y conce Po ey El PIOJO ls os e eee PLC MODE H owo EJOOJOJOIO 5 por FA CIOLOIOIO A MODE KEY Mode of Operation at Power up The DLO5 CPU will normally power up in the mode that it was in just prior to the power interruption For example if the CPU was in Program Mode when the power was disconnected the CPU will power up in Program Mode see warning note below WARNING Once the super capacitor has discharged the system may not power up in the mode it was in when this occurred There is no way to determine which mode will be entered as the startup mode However the PLC can power up in either Run or Program Mode if the mode switch is in t
42. rete bits CTO through CT17 therefore its alias is VCTO V41141 is the word memory reference for discrete bits CT20 through CT37 therefore its alias is VCT20 V41200 V41200 is the word memory reference for discrete bits SPO through SP17 therefore its alias is VSPO V41201 is the word memory reference for discrete bits SP20 through SP37 therefore its alias is VSP20 DLO5 Micro PLC User Manual 6th Edition Rev C 3 29 Chapter 3 CPU Specifications and Operation X Input Bit Map This table provides a listing of individual Input points associated with each V memory address bit for the DLO5 s eight physical inputs Actual available references are XO to X377 V40400 V40417 DLO5 Input X Points RSI ED Address 5 007 006 005 40400 DLO5 Option Slot np X mais Address 9 8 7 4 111 110 107 106 105 104 V40404 Y Output Bit Map This table provides a listing of individual output points associated with each V memory address bit for the DLO5 s six physical outputs Actual available references are YO to Y377 V40500 V40517 DLO5 Output Y Points ENS Address 005 40500 10 This table provides the listing for the individual option slot Output points available DLO5 Option Slot Output Y Points
43. s is installed The super capacitor will retain the values in the event of a power loss but only for a WARNING The DLO5 PLCs do not have battery back up unless the memory cartridge DO 01MC AN short period of time depending on conditions DL05 Micro PLC User Manual 6th Edition Rev C 3 Chapter 3 CPU Specifications and Operation Using a Password A The DLOS PLCs allow you to use a password to help minimize the risk of unauthorized program and or data changes Once you enter a password you can lock the PLC against access Once the CPU is locked you must enter the password before you can use a programming device to change any system parameters You can select an 8 digit numeric password The Micro PLCs are shipped from the factory with a password of 00000000 All zeros removes the password protection Ifa password has been entered into the CPU you cannot just enter all zeros to remove it Once you enter the correct password you can change the password to all zeros to remove the password protection WARNING Make sure you remember your password If you forget your password you will not be able to access the CPU The Micro PLC must be returned to the factory to have the password along with the ladder project cleared from memory It is the policy of AutomationDirect to require the memory of the PLC to be cleared along with the password You can use the D2 HPP Handheld Programmer or
44. ser Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation WARNING You may never have to use this feature unless you want to clear any setup information that is stored in system memory Usually you ll only need to initialize the system memory if you are changing programs and the old program required a special system setup You can usually load in new programs without ever initializing system memory Remember this AUX function will reset all system memory If you have set special parameters such as retentive ranges etc they will be erased when AUX 54 is used Make sure you that you have considered all ramifications of this operation before you select it Setting Retentive Memory Ranges The DLOS PLCs provide certain ranges of retentive memory by default The default ranges are suitable for many applications but you can change them if your application requires additional retentive ranges or no retentive ranges at all Appendix F has more information pertaining to the different types of memory The default settings are Memory Area Default Range Available Range Control Relays C400 C777 CO C777 V1400 V7777 VO V7777 None by default TO T177 CTO CT177 CTO CT177 None by default S0 377 You can use AUX 57 to set the retentive ranges Appendix A contains detailed information about auxiliary functions You can also set the retentive ranges by using Setup in DirectSOFT 5 PLC gt Setup gt Retentive Range
45. smit Data RS232C 4 TXD __ Transmit Data RS232C 5 5V Power conection 5 RTS Request to Send 6 pin Female 6 OV Power connection GND 6 OV Power connection GND Modular Connector N RUN STOP TERM PORT 1 PORT 2 SN Top View il Tm am PORT 1 PORT 2 Communication Port 1 Communication Port 2 Com 1 Connects to HPP DirectSOFT operator interfaces etc 6 pin RS232C 9600 Baud Fixed Parity odd default Station address 1 fixed 8 data bits 1 start 1 stop bit Asynchronous Half duplex DTE Protocol Auto Select K sequence Slave only DirectNET Slave only Modbus RTU Slave only 3 4 Com 2 Connects to HPP DirectSOFT operator interfaces etc 6 pin RS232C Communication speed baud 300 600 1200 2400 4800 9600 19200 38400 Parity odd default even none Station address 1 default 8 data bits 1 start 1 stop bit Asynchronous Half duplex DTE Protocol Auto Select K sequence Slave only DirectNET Master Slave Modbus RTU Master Slave Non sequence Print DLO5 Micro PLC User Manual 6th Edition Rev C Chapter 3 CPU Specifications and Operation Connecting the Programming Devices If you re using a Personal Computer with the DirectSOFT 5 programming package you can c
46. tem to sense a change in an input point and update a corresponding output point In the majority of applications the CPU performs this task in such a short period of time that you may never have to concern yourself with the aspects of system timing However some applications do require extremely fast update times In these cases you may need to know how to determine the amount of time spent during the various segments of operation There are four things that can affect the I O response time e The point in the scan cycle when the field input changes states e Input Off to On delay time e CPU scan time e Output Off to On delay time The next paragraphs show how these items interact to affect the response time Normal Minimum I O Response The I O response time is shortest when the input changes just before the Read Inputs portion of the execution cycle In this case the input status is read the application program is solved and the output point gets updated The following diagram shows an example of the timing for this situation DLO5 Micro PLC User Manual 6th Edition Rev C 3 15 Chapter 3 CPU Specifications and Operation Scan Solve Solve Solve Solve Scan Program Program Program Program 5 Read Write Fa Inputs Outputs Field Input CPU Reads CPU Writes all Inputs Outputs Input Off On Delay Output Off On Delay ps h O Respo
47. ult Values Ranges V7657 Port 2 Setup completion code used to notify the completion of the parameter setup Default DADO V7660 Scan control setup Keeps the scan control mode Default 0000 V7661 Setup timer over counter Counts the times the actual scan time exceeds the user setup time V7662 V7717 Reserved V7720 V7722 Locations for DV 1000 operator interface parameters V7720 Titled Timer preset value pointer V7721 Title Counter preset value pointer V7722 HiByte Titled Timer preset block size LoByte Titled Counter preset block size V7723 V7750 Reserved V7751 Fault Message Error Code stores the 4 digit code used with the FAULT instruction when the instruction is executed V7752 V7754 Reserved V7755 Error code stores the fatal error code V7756 Error code stores the major error code V7757 Error code stores the minor error code V7760 V7762 Reserved V7763 Program address where syntax error exists V7764 Syntax error code V7765 Scan stores the total number of scan cycles that have occurred since the last Program Mode to Run Mode transition V7766 Contains the number of seconds on optional Memory Cartridge clock 00 59 V7767 Contains the number of minutes on optional Memory Cartridge clock 00 59 V7770 Contains the number of hours on optional Memory Cartridge clock
48. utput image register the CPU writes the contents of the output image register to the corresponding output points Remember the CPU also made sure that any forcing operation changes were stored in the output image register so the forced points get updated with the status specified earlier ES Diagnostics During this part of the scan the CPU performs all system diagnostics and other tasks such as calculating the scan time and resetting the watchdog timer There are many different error conditions that are automatically detected and reported by the DLO5 PLCs Appendix B contains a listing of the various error codes Probably one of the more important things that occurs during this segment is the scan time calculation and watchdog timer control The DLO5 CPU has a watchdog timer that stores the maximum time allowed for the CPU to complete the solve application segment of the scan cycle If this time is exceeded the CPU will enter the Program Mode and turn off all outputs The default value set from the factory is 200 ms An error is automatically reported For example the Handheld Programmer would display the following message E003 S W TIMEOUT when the scan overrun occurs You can use AUX 53 to view the minimum maximum and current scan time Use AUX 55 to increase or decrease the watchdog timer value I O Response Time Is Timing Important for Your Application T O response time is the amount of time required for the control sys
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