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Blū Logic User Manual and Reference

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1. ase pessi Besides contacts and coils Ladder Logic includes Timers Counters and Registers for making computations Bl Logic and some other versions also have Shit Registers and Sequencers Got it Here s another example Suppose you want to control a submersible pump You will want a start button with a sealing contact to keep the pump running after the operator takes his finger off of the button You will want a stop button Stop buttons in automation are normally closed so that the system will stop if a wire to the stop button breaks 8 Ver 30 Jan 2012 Blu Logic Intro to Ladder Logic A submersible pump application can suffer from backspin When the pump stops for some reason gravity pulls the effluent back down the pipe and spins the pump like a turbine in the opposite of the normal direction If you try to start the motor while it is backspinning you can break the shaft So a control needs to prevent a restart while the pump could still be back spinning This can be accomplished with a timer START STOP IR1 ma AO en A ERR T eee aceod IR1 Poa a IR1 TMR1 5 MIN TMR1 PUMP et hee ree OR es a By now you should be able to follow the sealing logic IR1 is an internal relay When the start button is pushed and the stop button is NOT pushed IR1 will be energized IR1 s contact then bypasses the start button and keeps IR1 energize
2. Used to move from one field to the next in a dialog this is standard Windows behavior Hold down SHIFT while you TAB to move backwards The DELete key erases the contents of selected cells It does the same thing as the wire cutter tool But the wire cutter can only clear one cell ata time You can click and drag the mouse to select a range of cells and then DELete them all with a single key stroke If you hold down SHIFT while you DELete the state of your automatic rip up preference is reversed That is if you have auto rip enabled and wires are normally ripped up when you delete holding down shift will NOT rip up wires outside of your selection If you have auto rip disabled in the preferences dialog holding down SHIFT while deleting will temporarily enable auto rip up RIGHT CLICK All right so it s not really a key If you right click on a timer counter shift register REG or IF element in the diagram you can modify it You can also right click on any of these assets in the Asset Palette to modify or rename them A4 Ver 22 Jan 2013 Blu Logic Reference Execution Time of Operations and Elements The following table will give you an idea of the amount of time each element adds to the scan time of a diagram This reference is intended to help you choose between alternate implementation strategies and is not completely precise in all cases For very small diagrams this table will under estimate the scan time For a lar
3. When you select a controller model for the first time Bl Logic will contact our servers and download a list of that model s assets and other information it needs to develop diagrams for a specific controller model In order to download Bl Logic must be able to access the Internet After a given controller model is downloaded one time Bl Logic will keep a copy of the information on your hard drive so it is not necessary to always have an Internet connection But it is necessary for your PC to be on line each time you ask Bl Logic to prepare a diagram for a controller model you haven t used before Blu Logic will remember your controller model between sessions If you have occasion to work with more than one model then you can specify the model when you create a new diagram Select New Controller Model from the File menu 1o My Ladder Diagram BLU File Edit Tools Reports Help New Controller Model Load Diagram Save Save As Recent Diagrams d Exit Using the Editor The Bl Logic ladder editor allows you to enter and modify logic in the form of a diagram Operation of the editor is very intuitive but even if you are an experienced ladder programmer you will want to review this section because there are some special tricks and keystrokes that are unique to this design If you don t want to read all of this well OK but at least glance at the Special Keys section in the reference
4. and predictability Relying on floating point math can hide anomalies that the control system designer really should be aware of Blu Logic provides 32 bit integer math Most small PLCs only supply 16 bits and this is adequate for the majority of control problems PLCs that do provide floating point normally use a 32 bit format commonly IEEE 754 single precision format All integer representation of process values is common In fact it s so common that many off the shelf man machine interfaces have built in capabilities to scale operator inputs and outputs to integer values The easy way to think about it is this figure out how many decimal places you need make sure you always have that many places even if some on the right are zeros Got that OK now just take away the decimal point Easy Suppose you want 3 decimal places Just multiply every number in the system by 1 000 You have to be careful when you multiply two such scaled values in an expression because the product of two numbers each scaled by 1 000 will be scaled by 1 000 1 000 So you have to divide the product by 1 000 once for each multiplication to keep the scale factor at 1 000 For example suppose you choose a scaling factor of 1 000 as suggested above The the quantity three and a quarter would be represented as 3 250 and the quantity one half would be 500 If you multiply these two numbers together you want the result to be one and five eights whi
5. Closed NC contact looks like It passes current when the corresponding physical input or coil is not energized With just these three elements logic of arbitrary complexity can be implemented There s actually a mathematical proof of that statement but won t bore you with it here Here is another example This one has two contacts A and B Because both contacts must be closed to complete the circuit and let current flow to the coil X this circuit implements a logical AND function Both A AND B must be closed to operate the coil X 6 Ver 30 Jan 2012 Blu Logic Intro to Ladder Logic lf there s an AND then there has to be an OR right In the following closing either A OR B will complete the circuit and operate the coil Suppose you need to implement a surge tank You have a constant in flow of product from some upstream process and you need to deliver it to a downstream step on demand Your surge tank will be equipped with a pump to send the product down stream and a pair of level sensors for the maximum and minimum levels of the tank Your controller would have inputs from the level sensors and the down stream demand signal and these will appear in the diagram as contacts Let s name them MAX This contact closes when the product reaches the upper level switch MIN Likewise this is the lower level switch It is closed when the product level is above some minimum and open when the level is below it DEMAND Ind
6. Integer Math Mating Connectors Phoenix Contact MSTB 2 5 XX S 5 08 Power 2 pole MSTB 2 5 2 S 5 08 I O Any combination of 24 total poles 5 to 95 RH Non condensing pimensione comectars MSO AG connectors Minimal rung defined as one NO contact and one normal coil Registers and internal coils share memory so limits interact Scan time guaranteed lt 1 mS for any mix of logic but no register operations BR O N gt Derate to 1 amp when supply lt 16V and temperature gt 50 C Math functions add subtract multiply divide modulo negate and bit wise NOT OR AND XOR Bl Logic programming software manual available on request Specifications subject to change without notice 24 Volt DC Power Input USB Programming Port Power Lamp Select encoder Adjust encoder Digital Output Lamps Relay K1 o e Relay K2 Lamp Lamp QQQQQOWOWOV QDOWOOWOOOOV Relay K1 N O Relay K2 N C Relay K1 C Relay K2 C Relay K1 N C Relay K2 N O Return Return Analog In 1 Analog Out 2 Analog In 2 Analog Out 1 Return Return Digital In 1 Digital Out 4 Digital In 2 Digital Out 3 Digital In 3 Digital Out 2 Digital In 4 Digital Out 1 Return Return Relay contacts are isolated All other I O returns are connected to negative pole of 24V power input USB port is also referenced to 24V power return Sourcing and Sinking For an electrical current to flow there must be a complete closed path f
7. Logic and the controllers it is compatible with support only integer math To the uninitiated this may seem like a major deficiency and to preclude working with fractional values In fact there are advantages to integer math and there are simple techniques for handling fractional values in an integer system Floating point math may seem to be more precise but this is not necessarily true and the fact that it seems true can lead to dangerous assumptions The technique of performing math on fractional values using only integers is known as fixed point Suppose you want to represent a value in the range of 0 to 100 You wish to be able to represent values which are a fraction of a percent For clarity let s say that you want to represent values between 0 and 1 since this is equivalent and that you want the maximum possible precision To represent this range of values in floating point is easy O is O a tenth is 0 1 half is 0 5 90 is 0 9 and 1 is 1 If you want to for example set the value of a 10 bit analog output from this value you multiply it by 1023 Let s represent this same range in integers with 8 decimal places So we map the range of O to 1 onto the range of integers from O to 100 000 000 O is O a tenth is 10 000 000 half is 50 000 000 and 90 is 90 000 000 If you want to set the value of a 10 bit analog output you divide by 97 751 i e 100 000 000 97751 1023 The integer representation is superior for sev
8. be opened if the MCR is turned off lf there is no MCR coil in a ladder diagram then the MCR is always on If there is an MCR coil anywhere in the diagram then the MCR will initially be off when the diagram starts scanning at power up None of the outputs will function until you turn on the MCR And you ll call tech support and they ll eventually figure it out and you ll feel like a fool It can happen to anyone Rung Execution Order Blu Logic guarantees that rungs are executed in the order that they appear in the diagram They are executed from the top of the diagram to the bottom The values of input contacts and output coils tied to physical I O points are frozen during the scan of the ladder That is the execution sequence is like this 1 Read all physical inputs and set the value of contact assets which are internal copies 2 Scan or solve the ladder diagram from top to bottom 3 Update all physical outputs to the value of coil assets Unless the MCR is off in which case all physical outputs will be turned off regardless of the state of their coils 4 Repeat Don t you always wonder when to stop shampooing Ladder diagrams never stop repeating Blu Logic allows more complex interconnections in a diagram than most ladder logic systems so we need to be careful with the definition of a rung A Bl Logic rung can have any number of connections to the power rail and the neutral rail and can have vertical and horizont
9. is active the key de selects any selected cells of the ladder Typically you will hit the ESC key after inserting several identical elements or at the end of wiring connections between elements with the screwdriver tool If you select one cell of the diagram by left clicking you can then move that selection around with the keyboard arrows This functionality is most often used in conjunction with clicking the Asset Palette to add elements to the diagram BACKSPACE Moves to the left one space and erases the contents of that cell The Backspace key is designed to be used when you are entering logic by clicking assets in the Asset Palette It is equivalent to hitting the left arrow followed by the DELete key SPACE BAR When a cell is selected or a tool that represents a contact or a coil is active you can hit the SPACE BAR to switch between the variants such as 43 Ver 22 Jan 2013 Blu Logic CTRL CTRL C CTRL V CTRL X CTRL Z TAB DEL SHIFT Reference NO NC RISE and FALL contacts You can change more than one ata time by selecting multiple elements and hitting the SPACE BAR If you hold down the control key while you click to select your previous selection is retained In this way you can build up a disjoint selection Copy selected cells Paste a copy of cells from the preceding Copy or Cut operation Cut copy and then delete selected cells Hold down Control and type Z to undo the last editing operation
10. is pulsed once for each movement of the line Downstream steps such as the fill station and the scrap diverter can refer to the appropriate contact corresponding to how many steps they are down the line from the inspection step The maximum size of a shift register is 32 bits If you need a longer register you can connect two or more together All Shift inputs should be pulsed together and the 32 contact of each shift register should be wired to the Data input of the next The shift registers must be shifted from the far end to the front In other words the stages should 28 Ver 22 Jan 2013 Bl Logic Language Details appear in the ladder diagram from the first stage at the bottom up to the final stage above all others Sequencers A sequencer can have up to 32 contacts and it closes them one at atime in turn At power up or when the Reset input is energized contact MySequencer 01 is closed and all others are open Each rising edge of the Step input opens the current contact and closes the next one A sequencer also has a Reset input that sets it back to the initial condition with contact 01 closed If you wire the highest numbered contact to the Reset input then the sequencer will repeat endlessly A sequencer can be used to control a step by step process Each of the sequencer s contacts activates one step of the process when it closes Like a shift register a sequencer can be extended beyond 32 contacts by daisy chaining tw
11. reached and stays on until the timer is reset Each rising edge of the input causes the counter register to increment The counter output turns on when the count is equal to or exceeds the preset The counter can be wired to reset itself at the preset value Each rising edge of the input causes the counter register to decrement The counter output is on when the count is zero The counter can be wired to load itself with the preset when it reaches zero An Up Down Counter is just like an Up Counter but with an additional input to make it count down The behavior of the output contact and the reset input are the same as an Up Counter Shift Register A shift register is a train of up to 32 bits that move over one space on Sequencer each rising edge of the SHIFT input The RESET input sets all bits to zero The shift register can be wired so that words shifting out the end are recirculated back to the beginning A sequencer has up to 32 contacts that energize one at a time Contact 01 is on initially or when the Sequencer is reset Each rising edge on the STEP input cause the current contact to open and the next to close A sequencer can be made to repeat by wiring the highest numbered output 42 Ver 22 Jan 2013 Blu Logic REG Reference to the reset input This element sets the value of a register to the result of a specified formula The formula can combine constants and register values including the registers in timers coun
12. single contact instance it is applied to Other contacts in the diagram with the same name are not affected unless each one has a clip lead or tag applied To force all contacts with a given name hold down the Shift key when clicking the tool on a contact Clip leads and Lockout tags can be removed by clicking the same tool on the sameame contact a second time In addition all clip leads and lockout tags can be removed from the diagram in a single step with the Clear clips and tags command in the Edit menu 17 Ver 22 Jan 2013 Blu Logic Downloading to a Blu Logic Controller Using Blu Logic To actually do anything with your ladder diagram it must be loaded into your controller Connect it to your PC with a USB cable If the controller is scanning at the time the USB cable is connected it will stop and turn off all outputs The controllers USB programming port is designed to emulate a Windows Human Interface Device HID This allows it to connect via the built in Windows driver hidusb sys rather than requiring a special driver The first time you connect a Bl Logic controller to your PC Windows may depending on the version display one or more dialogs to associate it with the HID driver Respond in the affirmative Some examples are shown below with the appropriate responses indicated Welcome to the Found New Hardware Wizard Windows will search for current and updated software by looking on your computer on th
13. Bl Logic User Manual and Reference BLU ow User Manual and Reference Cyclotronics manufactures electronic controllers for our customers products One thing that makes them unique is that they are programmed in Ladder Logic which is the most common paradigm for programming industrial controls Blu Logic is an integrated environment for developing ladder logic diagrams which can then be downloaded to our custom controllers Ladder Logic produces very robust and readable programs capable of executing multiple control processes synchronous or not concurrently Changing one section of or process in a Ladder Logic program is much less likely to affect another section than is the case with more computer oriented languages This manual introduces Ladder Logic in general explains how to use the Bl Logic program and includes a reference to all of the Ladder Logic elements available to build ladder diagrams for your controller Because all of our controllers are custom designed their features vary widely For example some have digital and analog I O while others have digital I O only Some have displays or screens and some have adjustable controls But the Blu Logic program and this manual apply to the entire line Therefore some of the features described in this manual may not be available on your particular model The Blu Logic program will not give you access to these features if you properly select the matching controller model when you
14. Bl Logic registers Registers can be displayed only or can be made adjustable by the user Itis good practice to avoid modifying in the ladder diagram values that the user can adjust as the resulting interaction can be confusing Ensure you have a register for each value to be displayed or adjusted As explained in the Bl Logic instruction manual you can create a register by clicking on the NEW REGISTER entry in the Register tab of the Asset Palette window Contact Coil Timer Counter Shift Reg Sequencer IF Register To configure a value to be displayed right click on the register name in the Register tab of the Asset Palette to bring up the register properties dialog Register Properties X Edit Register Name Value to be Displayed W Display on HMI Prefix TEMPERATURE Digits 3 Decimals fi Suffix a Enable value adjustment Cancel DELETE l 220ct12 Blu Logic Check the Display on HMI box Fill in the Prefix Digits Decimals and optionally the Suffix field They work as follows Prefix is text that appears to the left of the value on the display Normally this is a label for the value like TEMPERATURE Digits sets the total number of spaces that the number will occupy on the display This number includes all digits both to the left and the right of the decimal point one for the decimal point itself if Decimals is non zero and one space for the sign of the number if
15. TE key will clear all selected cells in a single operation There are other operations in the Edit menu which you can then invoke and the chosen operation will be performed on all selected cells Copy Cut and Paste When one or more cells of the diagram are selected you can copy them and then paste the copy elsewhere Cut is the same as copy but Cut will also delete the original instances Copy Cut and Paste appear in the Edit menu and can also be activated with the shortcut keystrokes Ctrl C Ctrl X and Ctrl V respectively Copying is complicated by certain syntactic rules such as you can only use one instance of a given timer or counter and all timers counters sequencers etc must be in the rightmost column In order to comply with these rules the Paste operation may refuse to paste an element which already appears elsewhere in the diagram and may relocate some elements to the right most column if you Paste a selection farther to the left than when you Copied it Insert and Delete Rungs The Edit menu also has Insert Rung and Delete Rung functions To insert a rung to open up space for more logic click anywhere in the rung and then choose Insert Rung from the Edit menu A new blank rung will appear above the rung you had selected If 15 Ver 22 Jan 2013 Blu Logic Using Bl Logic you select more than one row of the diagram by clicking and dragging then that same number of rungs will be inserted I
16. When you start the Bl Logic program it will present you with an empty ladder diagram in the main window Two additional windows will also open and can be positioned separately on your screen These are the Toolbox window and the Asset Palette The Toolbox includes the screwdriver for making connections the wire cutter for breaking them It also provides the alligator clip lead for temporarily shorting a contact and the lockout tag for temporarily forcing a contact open At the bottom of the toolbox is the sticky note tool which you can use to add comments to your diagram 12 Ver 22 Jan 2013 Blu Logic Using Bl Logic Shift Reg Sequencer IF Register Contact Coil Timer Counter Toolbox Asset Palette Using the editor in general consists of selecting a tool or an asset applying it to the diagram one or more times selecting another tool and so on The tools in the Tool Box can also be selected by using the function keys F1 through F5 Press the ESC key to deselect the current tool Assets and the Asset Palette The Asset Palette shows you a list of the coils contacts and registers for your Blu controller In a new diagram only the built in coils and contacts corresponding to the I O points of your particular Bl Logic controller will appear You can rename the built in assets to correspond to your application And you can create internal relays timers counters shift registers sequencers and additional
17. a viani iaaa ea e a e aer iea ea ea HP a aasar Nt dor eaea eiaa aae aaea esanaia adea aeea aeea There are three kinds of counters An Up Counter increments its register on each rising edge of its input A Down Counter decrements on each rising edge Each counter is assigned a preset value An Up Down counter has both Up Count and Down Count inputs and can count in either direction All three timers have a Reset input Counters count on the rising edge of an input That is they do not count on each scan that the input is energized only on the first scan that it becomes energized following one or more scans of being de energized An Up Counter starts at zero and counts up When the preset value is reached the counter contacts close The counter freezes at the preset value and ignores additional Up count pulses Often a counter contact is wired to the counter s Reset input to zero the counter at this point If this is the case then the counter contact closes for a single scan pulse A Down Counter starts at its preset value and counts down When the count reaches zero the contacts close As with the Up Counter the counter s contact can be wired to the Preset input to make it emit a single scan pulse and automatically recycle Otherwise the counter will freeze at zero with the contacts remaining continuously closed The Preset input to a Down Counter causes the preset to be loaded into the counter To un freeze the counter energize its Pre
18. above discussion is very decimal centric But the hardware processor in your controller works in binary The scale factor does not have to be a power of 10 If you choose a scaling factor that is an integer power of two then the math operations can be performed more quickly Dividing by 1024 is about 10 times faster than division by 1000 Some of the fastest numbers to divide by are 65536 256 131072 2 and 4 For more information on this subject check out the Wikipedia articles on Fixed point Arithmetic and Binary Scaling or Chapter 9 of Embedded Systems Building Blocks Second Edition by Jean J Labrosse 39 Ver 22 Jan 2013 Blu Logic Reference Reference Blu Logic Elements Contacts GEOG HENE Normally open contact Can represent a hardware digital input the current state of a digital output an internal relay or a discrete output from one of the built in peripherals Normally closed contact This contact is closed when the corresponding input or coil is de energized and open when the input is energized Rising edge detector The output of this element is true for one scan of the ladder after a false to true transition of the associated coil or physical input The effect is a pulse for each rising edge on the input Falling edge detector The output of this element is true for one scan of the ladder after a true to false transition of the input Standard coil which can represent a ph
19. ages unless the ladder diagram explicitly provides a path from one to the other Blu Logic provides Modbus Ox coils and Modbus 4x registers Modbus commands which operate on Ox or 1x values will access the coils Modbus commands which operate on 3x or 4x registers will access the registers Modbus register values are only 16 bits long They can be treated as signed values from 32 768 to 32 767 or as unsigned values from O to 65 535 Bl Logic registers and computations support 32 bit values This means some care must be taken when passing numbers back and forth between a Blu Logic ladder diagram and a Modbus device Note that as long as you only deal with values within the unambiguous range of O to 32 767 you don t have to worry about the following lf a Modbus register is referenced in a Bl Logic expression such as in an IF or REG element then the Modbus value is assumed to be unsigned If the Modbus value is 33 Ver 22 Jan 2013 Bl Logic Language Details actually signed this will result in unexpected behavior For instance 23 written to a Modbus register and then copied to a Bl Logic register would come out as 65 513 BIO Logic provides a math function to solve this problem The function SXTND for Sign eXTeND converts a signed Modbus number to a 32 bit signed Bl Logic value There is also a Zero eXTeND function ZXTND which does the same thing for unsigned Modbus numbers If you don t use either functio
20. agram to the bottom 2 The order of evaluation within an interconnected rung is unpredictable and may even change when seemingly unrelated changes are made to the diagram Timers and Counters Timers and Counters are similar elements and have some common features The big difference is that timers count by themselves and counters only count when an energized input tells them to Each includes a register that contains the count or elapsed time Each contains a preset register which is compared to the counter timer register Each includes a contact which closes based on a comparison between the register and the preset There are three kinds of timers in Bl Logic On Delay Off Delay and Stopwatch The On Delay timer starts timing when its input is energized and closes its contacts when the timer reaches its preset At this point the timer stops running and the 24 Ver 22 Jan 2013 Blu Logic Language Details contacts will remain closed as long as the input is still continuously energized When the input is de energized the contacts instantly open and the timer resets to zero If the input is de energized before the preset time is reached then the timer resets immediately and the contacts will never close at all An Off Delay works the same way but the timer runs when the input is de energized and the contacts open when the preset is reached Any time the input is energized the contacts are closed A Stopwatch timer r
21. al wiring that crosses without connecting Wiring can even cross other rungs For purposes of the execution sequence guarantee a rung is a collection of elements with wired connections between them If there are no wired connections other than through the power and neutral rails between two groups of elements then they are not in the same rung 23 Ver 22 Jan 2013 Blu Logic Language Details Note that an isolated section of elements meeting this definition could actually appear in the middle of another rung because all connections could cross the isolated rung without actually connecting to it In this case the rung with the upper most connection to the power rail executes first including elements above and below the isolated rung and then the isolated rung executes But it s best not to create such a confusing situation in the first place Although Blu Logic lets you build very complex rungs this doesn t mean you always have to It is generally good practice to keep individual rungs simple It makes the diagram easier to understand and troubleshoot at some later date Remember it is common for ladder based automation systems to run for many years without any changes or program maintenance It is entirely possible that nobody will need to work on your program until after you have retired With the above in mind you only need to Know two simple rules about execution order 1 Rungs are evaluated in order from the top of the di
22. and feed it to a counter As in the above example one common application of a timer is to generate a periodic pulse This can be implemented with either an On Delay or an Off Delay timer but the On Delay version is perhaps more clearly self documenting Connect the timer s input to the power rail through a Normally Closed contact of the timer itself When the system starts that contact will be closed It will stay closed for the interval preset in the timer Once the timer reaches the preset it opens the NC contact this stops and resets the timer which closes the contact again and the process repeats The timer s contacts will be closed for a single scan every time the timer expires Any number of copies of 26 Ver 22 Jan 2013 Bl Logic Language Details the timer s contact can then be positioned elsewhere in the diagram to trigger something periodically A typical application for this trick is to advance a Sequencer by pulsing its Step input i a ee ae eee ee ll ee ie dD et le ee ed ee Aai ii rabid ataa Med Medina ba K eeii Mend NaS ood Meat eeaeee tata Nol Not Ko oeda Aaa a aaide iho MMM Med tleal Mal Sekt Nate l Naan Sei ielea gland dha Won Me dathoM May eaoaai ta Mo then ar Meta oBlend ag aeiee eaa pl Mel odas i I OI IN NY I I TY A NI I If NT htt I NO a i SO OOO a a OOO OSS OOS a SS OOP a a a a a a POO SS OOS a aaa aa aa a a aa aaa aa a r ai eaaa a a aaa Ta eadra eieaa TN aeea ae He hh aaae aa a aaa eaa
23. auxiliary window disappears when you close the formula editor Sticky Notes The sticky note tool lets you add notes to your diagram Click on the yellow sticky note in the toolbox Then move the cursor over the diagram to where you want the note and click A dialog will pop up and allow you to enter the text for your note Click OK when done You can move and edit sticky notes later To reposition a note left click on it and drag it to the new position To edit or delete the note right click on the note An editing dialog will appear 16 Ver 22 Jan 2013 Blu Logic Using Bl Logic Clip Leads and Lockout Tags The Clip Lead and the Lockout Tag are used to temporarily force the state of a contact without irreversibly changing your diagram If a clip lead is applied to a contact it will always pass current regardless of the state of the coil or external input That is the contact will always act as if it was closed Note that in the case of a normally closed contact this is equivalent to not operating the corresponding physical input or internal relay coil Either an NO or NC contact will pass current when bypassed by a clip lead The lockout tag does the opposite It forces a contact to be open A tagged contact will not pass current Clip leads and Lockout tags are applied by clicking on the corresponding tool in the Toolbox and then clicking on a contact or an IF element A clip lead or lockout tag only affects the
24. ch should be represented as 1 625 But the product of two quantities scaled by 1 000 will be scaled by 1 000 000 1 000 times 1 000 That is the result of the example will be 1 625 000 You can fix this by dividing by 1 000 to remove the extra scaling factor You have to be careful that the intermediate value the product before the division does not exceed the range of 32 bit integers 2 147 483 648 to 2 147 483 647 You may think that you do not have to worry about this in floating point calculation but the truth is that if your intermediate product exceeds 24 bits of significance the binary fraction will be truncated resulting in a loss of precision which is hidden from you Don t just blindly convert every multiplication into a multiplication and a division Think about the scale factor on a system level You may find that you only have to perform one division or even none depending on the ranges of inputs outputs and constants Try to combine all of the constant scaling factors such as the conversion of an analog input to engineering units the fixed point scale factor and the conversion from engineering units to a value for an analog output into a single operation For example you might multiply the analog input reading by a constant perform all calculations in the scaled units divide the final result by a second constant and end up with a suitable value for the analog output 38 Ver 22 Jan 2013 Blu Logic Integer Math The
25. d until the stop button is pressed Notice that you do NOT use a Normally Closed contact to represent the stop button The button itself is a normally closed switch A Normally Closed contact reverses the sense of any kind of switch The NO contact in the example OPENS when the stop button is pushed because that is when the button s electrical switch opens It might help to think of the stop button as an enable switch which is closed until someone pushes on it TMR1 is an On Delay Timer When IR1 closes and energizes the input to the timer it begins to run When it reaches its preset of 5 minutes the timer s contacts will close and energize the pump An On Delay Timer does not delay turning off If the stop button is pressed and IR1 is de energized the timer s contacts open immediately and shut off the pump The physical output associated with the Pump coil is normally not the pump motor itself but a contactor or motor starter which handles the larger load of the motor This introduction has presented the basics of Ladder Logic There s more to it although less than you might think We haven t touched on analog I O nor explained counters and other flavors of timer Refer to the Reference section of this manual for a complete list of the elements available in Blu Logic 9 Ver 30 Jan 2012 Blu Logic Intro to Ladder Logic In theory a ladder diagram is a set of rules that are applied concurrently just as physical rela
26. e 30 Ver 22 Jan 2013 Bl Logic Language Details Mathematical Expressions Formulae The REG and IF ladder logic elements require what computer scientists call an expression and the rest of us call a formula to be entered In the REG case when the expression is evaluated the register is set to the result of the calculation In an IF element the result is compared to the contents of the specified register Expressions consist of terms combined with operators Terms may be numerical literal constants like 42 or register names Operators are and for integer math or amp and for bitwise boolean operations Register names are strings of characters words Aregister name has to start with a letter A through Z but may also contain digits O through 9 the underscore _ and spaces The maximum length of a register name is 20 characters The names are not case sensitive and any space characters are there only for readability and are not significant otherwise That is the register name My Register refers to the same register as myregister or even myREglster Just to be clear all other characters including the underscore are significant My_Register is not the same as MyRegister or My Register When you create a timer or counter the system will make up some register names These names always contain a period so you won t accidentally create your own register name which match
27. e Diagram scan time is greatly reduced in troubleshooting mode How much so is a complex function of computer speed USB network speed and topology and diagram complexity but it will definitely scan more slowly than the stand alone controller with the 19 Ver 22 Jan 2013 Blu Logic Using Bl Logic USB cable disconnected This change in timing may cause a dramatic change in the behavior of your diagram Depending on what you are controlling it could even be dangerous so consider the consequences before using troubleshooting mode and troubleshoot with the outputs disabled if at all possible When you select Troubleshooting from the Tools menu a dialog appears with three buttons Troubleshoot x j n MV Output Disable The Reset button performs the power up initialization of the diagram as described on page 33 including setting the RESET contact The Scan button will start and stop scanning The Single button will cause the controller to execute a single scan through the diagram and then pause until you press Single or Scan again Single scanning can be used to study your logic in super slow motion detail While running in Troubleshooting mode an LED is displayed just to the lower right corner of each contact or coil indicating it s logic state The value in a timer or counter register is displayed in the upper right corner of the timer or counter The value of other registers are displayed next to IF and REG eleme
28. e associated physical output or internal relay turns on It stays on even when the input to the SET coil is turned off An energized input to the RESET coil of the same relay will un latch the relay and turn the output back off If both SET and RESET coils are on in the same rung the result is indeterminate and may be unpredictable P iad Toggle A TOGGLE coil will cause the state of a latching coil to be reversed If the output was on an energized TOGGLE will turn it off and vice versa A TOGGLE is only sensitive to a rising edge on its input If the input is maintained the relay won t constantly toggle on and off 22 Ver 22 Jan 2013 Bl Logic Language Details If you use a SET RESET or TOGGLE coil with any relay then it is defined as a latching relay If you try to combine a normal coil with latching relay coils in the same relay you will get an error when you try to download the diagram to your controller Every Blu Logic diagram has one Master Control Relay called MCR If the MCR is off then all physical outputs will be turned off regardless of the state of associated coils in the diagram Contacts associated with an internal relay will still operate even if the MCR is off The state of latching relays is also not affected by the MCR The MCR interrupts the signal between the coil and the physical circuit It does not affect the logic of the diagram However you can put MCR contacts in your diagram and these will
29. e hardware installation CD or on the Windows Update Web site with your permission Read our privacy polic Can Windows connect to Windows Update to search for t Yes this time only C Yes now and every time connect a device No not this time Hardware Installation A The software you are installing for this hardware HID compliant device has not passed Windows Logo testing to verify its compatibility with Windows XP Tell me why this testing is important Continuing your installation of this software may impair or destabilize the correct operation of your system either immediately or in the future Microsoft strongly recommends that you stop this installation now and contact the hardware vendor for software that has passed q dows Logo testing Lontinue Anyway i ound New Hardware Wizard This wizard helps you install software for USB Human Interface Device If your hardware came with an installation CD lt lt or floppy disk insert it now What do you want the wizard to do Install the software automatically Recommended ES 37 Install from a list or specific location Advanced ick Next to continue lt Back Next gt Cancel ound New Hardware Wizard This wizard helps you install software for HID compliant device If your hardware came with an installation CD lt 6 or floppy disk insert it now What do you
30. en you select an asset the cursor changes to the graphical representation of that element which we call the tool This is also true of the wire cutter sticky note and screwdriver To de select any tool hit the ESC or ESCAPE key on the keyboard If the currently selected tool is a contact you can hit the space bar on your keyboard to rotate between NO NC RISE and FALL variants For a coil you can rotate between COIL SET CLEAR and TOGGLE If you select a coil from the Asset Palette it will appear as a coil only over the right most column of the ladder diagram Anywhere to the left it will appear as a contact If you use it as a contact it reflects the current state of the coil This is naturally how internal relays are employed but you can do the same thing with any output point When you click on the diagram with a tool any circuit element previously occupying that cell is replaced Blu Logic includes an alternate way for the experienced user to enter logic elements To use this method you must first make a change in the preferences Click Edit and choose Preferences Make sure Clear selection when an asset or tool is clicked With this option checked as it is initially any time you click on an asset in the asset pallet or a tool in the tool box any selected cells are de selected With the option unchecked you can select a cell and then click an asset to enter it in that cell Try this Click on an empt
31. eral reasons First computations can be much faster resulting in a faster overall scan time Second you may be surprised to know that certain easy values such as 0 1 and 0 9 cannot be precisely represented as a binary fraction Just as a third cannot be precisely represented by a precise decimal fraction because it is an infinite repeating decimal of 0 3833333 the binary representation of a tenth is a repeating binary fraction and thus cannot be precisely represented no matter how many bits you have Third the integer representation is more precise IEEE 32 bit floating point format only uses 24 bits to represent the mantissa the significant digits Other bits of the 32 bits of storage must be reserved for the sign and the exponent A 32 bit integer uses all 32 bits for the mantissa In short the precision of representing O to 1 in floating point is 1 part in 16 million approximately 7 decimal places whereas the precision of representing O to 1 in the integer form described above is 1 part in 100 million 8 decimal places The available precision of a 32 bit integer is a little more than 9 decimal places Floating point is valuable if you need to represent very large numbers and very small numbers or when the range of possible values is not known in advance But in a control system we are more likely to know the possible range of values and we are more 37 Ver 22 Jan 2013 Blu Logic Integer Math interested in precision speed
32. es a system generated name For example each timer has two registers MyTimer TIM which is the actual timer and MyTimer PRE which is the preset register Constants can be either decimal or hexadecimal A decimal constant is simply a string of the digits O through 9 A hex constant is introduced by a and can include O through 9 and A through F digits For example 2A has the same value as 42 Operators follow a pretty standard precedence order Multiplication is performed before addition so that 2 3 4 results in 14 and not in 20 The precedence can be explicitly controlled by using parentheses A sub expression in parentheses will be evaluated first so 2 3 4 is equal to 20 Operators with equal precedence are evaluated from left to right Operators in Precedence Order Subexpression in parentheses Unary negation Boolean NOT Multiplication Division Modulus Addition and Subtraction 31 Ver 22 Jan 2013 Bl Logic Language Details Bitwise shift left and shift right Bo Bitwise logical AND Bitwise logical exclusive OR E Bitwise logical inclusive OR Expressions are limited to 100 characters If this is not enough you ll have to use shorter register names or break your expression up into multiple REG rungs If you have spaces in your register names or between operators you can take these out to make the most of the 100 character limit The values in registers are signed 32 bit integers So their range is limited t
33. es from off to energized You can think of the output as a pulse which fires ona rising edge of the input A FALL contact 21 Ver 22 Jan 2013 Bl Logic Language Details is the opposite of a RISE contact A FALL contact is closed for the single scan during which its associated physical input or internal coil is first de energized following a period of being energized Every Bl Logic controller has a contact named RESET This contact is closed for a single scan of the ladder at startup You can use it to set up initial conditions such as latching on the MCR for example Blu Logic features two kinds of relays normal and latching A normal coil is represented by in the ladder diagram It must appear in the right most column of the diagram touching the neutral rail It doesn t really have an output per se its connection to the neutral rail is part of the physical wiring analogy represented by ladder logic When the left side of a coil is energized the corresponding physical output will be turned on When the input is de energized the physical output turns off An internal relay may have any number of contacts and any number of coils When an input to a coil of an Internal Relay is energized then all of that Internal Relay s contacts will operate A latching relay can have three different types of coils and any number of each type PE Set Oooo Reset Oooo When the input to a SET coil is energized th
34. esenting the hot and neutral power lines The rungs of the ladder are combinations of switch contacts and loads like lamps or relay coils connected together with lines representing wiring When a combination of switches is on the current can flow from the hot rail through the switches and loads to the neutral rail Ladder Logic is a computer programming language in which the programs are ladder diagrams It doesn t look like a program but it is Computer software or sometimes a patient engineer can translate the ladder diagram to a series of instructions which are executed by a controller The diagram delivers the same behavior that a physical circuit of actual relays timers etcetera would deliver if wired according to the diagram Ladder Diagrams have been around for over a century Ladder Logic was invented in the late 1960 s by a group of engineers trying to simplify the complex task of wiring relay logic to build control systems for automation in the auto manufacturing industry Dick Morley was part of the team and is widely recognized as the father of the Programmable Controller and Ladder Logic His many other accomplishments include anti lock brakes The original idea was that a ladder diagram was much easier to understand than a conventional computer program and could be used by engineers who were not trained in computer programming then mostly written in arcane assembly language These days most engineers who work with a
35. f you insert a rung between two or more rungs which are connected vertically these vertical connections are automatically extended through the new rungs You can easily delete these connections if they are not required Click and drag to select your rung or rungs hold down SHIFT and click the DEL key on the keyboard Reconfiguring Assets When you create a new asset a small dialog window pops up and lets you name and configure the new asset To change this information later right click on the element in the diagram or on the master copy of it in the Asset Palette This will pop up the dialog again and let you make changes If you change the name of a register that is referred to in formulas elsewhere in REG and IF rungs the program will offer to automatically change all of these references to the new name Normally you will want to take advantage of this assistance x Counter name up to 20 characters Counter Type My Counter Count Up Counter Preset C Count Down a Up Down Cancel DELETE Each REG and IF element includes a formula the result of which is either compared to the register or assigned to it If you right click on one of these elements in the diagram you can edit the formula Only that one instance will be affected by the change When editing a formula an auxiliary window pops up with the names of all registers At any time you can click a register in this list as a fast way of typing it The
36. ge diagram with a lot of math it will over estimate scan time Scan time can also vary slightly from one scan to another especially if serial communication is in use Because not all controller designs run at the same speed these times may vary between models However the relative speed of these operations is the same across the entire family at the time of this writing No matter how fast a regular coil executes it is always twice as fast as a toggle coil for example 250 nS Register name in expression 125 nS Negation or subtraction nS nanosecond 1 1 000 000 000 seconds US microsecond 1 1 000 000 seconds 45 Ver 22 Jan 2013 SLO Appendix This appendix provides supplemental information about your particular controller model Bld Logic Demonstrator Blu Logic Blu Logic Demo PLC User Interface Addendum This document is a supplement to the Blu Logic user reference manual You should have read that manual and will need to be familiar with the Blu Logic program in general before this material will make sense Your Bl Logic demonstrator includes a user interface comprising an LCD display and a pair of knobs The display can show up to four values at a time The left knob selects a value to be adjusted and the right knob adjusts that value up or down If more than four values are configured for display the left knob will also scroll the display to reveal the other values Values on the display come from
37. icates that the downstream process wants product You ll also need some outputs which will appear as coils in the ladder diagram PUMP Energize this coil to pump product down stream HOLD Tell the upstream process to pause ALARM Warn someone that we have a problem So the first thing you need is to turn on the pump when the downstream process requests product You ll want to stop the pump if the tank is pulled down below the minimum level Your rung will look like this DEMAND MIN PUME And if the tank level does fall below the minimum switch we need to alert an operator We re only going to sound the alarm to alert the operator if the downstream demand signal is on but once the alarm is activated we want to keep it on until the low level sensor is activated again We ll use an internal relay IR1 for this Note that the second 7 Ver 30 Jan 2012 Blu Logic Intro to Ladder Logic rung below latches the internal relay until the level rises above the MIN switch operates the switch and opens the corresponding NC contact even if the demand signal goes away in the meantime DEMAND MIN TRI aa a A a aaa lee O Nieto TRL sc aaa IR1 ALARM aal Chea ee ee C eS See And finally if we ever see MIN de energized implying the level is below the MIN switch and MAX energized implying that the level is above the MAX switch at the same time we know something is wrong MIN MAX ALARM
38. is unpredictable Reports Under Reports in the main menu you will find the following choices Print Diagram This does exactly what it sounds like The ladder diagram is printed out on paper This is useful for documentation when you are trying to trouble shoot your logic or as a way to communicate the machine s logic to other personnel Index The printout of a very large diagram may span many pages To help you find your way around in it print an Index report The Index lists all of the assets Contacts Coils Timers Counters etc in alphabetical order It describes what type of asset each is Then it shows the line numbers found on the diagram printout for each rung in the ladder where an instance of that element appears Asset List The printed Asset List report shows a list of all assets and shows some of the internal details associated with the elements If you rename some of the built in assets the Asset List may be helpful in deciphering which physical terminal of the controller is associated with which logical asset Otherwise you will not normally have any use for this information but factory support personnel may ask for it Troubleshooting Blu Logic features a Troubleshooting function in which the controller scans your diagram while still connected to the PC via the USB cable This allows Blu Logic to display the states of contacts and coils and the values of timers counters and other registers as they chang
39. it becomes negative For example 4 Digits could represent any of the following I III I pa Dr Dar O oc J JID J 1 Decimals sets the number of decimal places All Blu Logic values are integers So when you set a number of decimals the decimal point is inserted into the integer value For example if you set 3 decimals and the value in the register is one thousand then you would see 1 000 on the display As explained above the number of decimals and one for the decimal point are included in the number of Digits Suffix specifies text that appears to the right of the displayed value It is typically used for units such as mm V etc The button on the dialog allows you to enter a degrees symbol for a temperature unit such as C The width of each line of the display is 20 characters Thus the total of the length of the prefix Digits and the length of the suffix must not exceed 20 To allow the user to adjust a displayed value check the Enable value adjustment box in the register properties dialog When the diagram is scanning rotating the Select knob will move the underscore cursor through the digits of each value Rotating the Adjust knob will increase or decrease the value at the selected digit 2 220ct12 DEMO PLC SPECIFICATIONS CPU Specifications SS Program Memory 16K Instructions Approx 2 500 minimal rungs MO and two encoder knobs Programming Bl Logic Ladder Language IDE Sequencers
40. n the behavior is as if you used ZXTND ZX TNO MB RES O2 Going the other way from a 32 bit Blu Logic register to Modbus can also cause surprises Because the 32 bit number must be truncated values outside the range which can be represented by 16 bits will change If a Bld Logic register with the value of 100 000 is written to a Modbus register the value seen by the Modbus device will be either 34 464 if the Modbus device treats it as unsigned or 31 072 if the Modbus device treats it as signed As a precaution you may want to limit the range of values before writing them to Modbus registers 34 Ver 22 Jan 2013 Bl Logic Language Details Controller Startup When your controller is powered up or when the USB cable is unplugged after downloading a diagram an initialization is performed before the ladder begins to scan All latching relays are turned off All Timers are set to O All Up and Up Down Counters are set to 0 All Down Counters are set to their Preset value All Shift Registers are filled with zeroes All Sequencers are reset and thus their number 01 contact closes If there are any MCR coils in the diagram the MCR is turned off Otherwise it is turned on All other registers are set to 0 e The special contact RESET is closed It will open at the end of the first scan and never close again until the power is cycled 35 Ver 22 Jan 2013 Blu Logic Integer Math Integer Math Blu
41. nes and even entire factories There are many good resources available for learning more about Ladder Logic From Wikipedia to paper books such as Programmable Logic Controllers an introduction by W Bolton The web site www plcs net offers a popular book about Ladder Logic and includes an extensive online tutorial and an interactive forum for discussing PLCs in general and Ladder Logic in particular 10 Ver 30 Jan 2012 Blu Logic Using Bl Logic Using Blu Logic Installation Blu Logic requires a computer with the Microsoft Windows operating system It is compatible with Windows XP 2000 Vista and Windows 7 Compared to most Windows software installation of Blu Logic is very simple You just download the program to your desktop When you are ready to use it double click to launch the program There are no additional drivers DLLs or other special files to install To un install Bl Logic just delete the file from your desktop Blu Logic is not very resource intensive and should run well on even the slowest PC you can buy these days It does require a USB port to connect to your controller Each Bl Logic ladder diagram you create is saved in a single file with the extension BLU You choose where you wish to store these files on you hard drive Some users will want to keep them with other documents relating to the same project Others will want to create a single common folder and store all of their Bld Logic ladder diag
42. nter element is scanned Shift Registers A shift register holds a train of 1 and O bits You set the length of the train when you click on New Shift Reg in the Asset Palette The maximum length is 32 bits For each bit in the shift register there is an associated contact These are identified by the name of the shift register and a number such as MyShifter 01 MyShifter 02 and so on up to the number of bits you specified when you created the shift register Each shift register has a Data and a Shift input Each rising edge of the Shift input will cause all of the bits to move over one space Bit 1 will replace bit 2 bit 2 will replace bit 3 and so on The state of the Data input at that time determines the new value of bit number 1 If the data input is energized a 1 will be inserted Otherwise it will be a O The bit that shifts out the other end is lost You can cause the shift register to recirculate by wiring a contact for the last bit to the data input Now the bits can be thought of as going around in a circle Shift registers are commonly used to track the state of a workpiece in a pipelined series of operations If an inspection operation determines that a bottle is broken for example a later process step should not fill it with product and a still later step should push it off the line into a reject chute To implement this the Data input of a shift register is controlled by the output from the inspection step The Shift input
43. nts Tick TIM 33 The Output Disable checkbox forces the MCR Master Control Relay to be open at the beginning of each scan Your diagram can still turn the MCR back on So the checkbox is not a complete guarantee that an actuator will not operate unexpectedly When you re done with troubleshooting mode close the troubleshooting dialog by clicking on the X at the right side of the title bar Your controller must be connected to the PC to use Troubleshooting mode but the I O and power terminals do not have to be connected to anything 20 Ver 22 Jan 2013 Bl Logic Language Details Language Details Contacts and Coils Blu Logic supports four kinds of contacts NO NC RISE and FALL Normally open contacts look like this A Normally Open NO contact is closed passes current when the corresponding physical input is energized It is open otherwise For an internal relay an NO contact is closed when the corresponding coil is energized and open otherwise Each physical output can also be referred to by contacts that reflect its state For a given physical input physical output or internal relay any number of contacts may be used in the diagram A Normally Closed NC contact is just the opposite It is closed when the corresponding physical input physical output or internal relay is de energized A RISE contact is closed for the single scan during which its associated physical input or internal coil chang
44. o about plus and minus two billion All math is also performed in 32 bits Division by zero does not cause an error but results in either the maximum possible value 2 147 483 647 or the minimum possible value 2 147 483 648 depending on the signs of the operands Division is the slowest math operation Division takes 25 times as long as multiplication so a lot of division operations can quickly increase the scan time Modulo uses division so it is also slow An exception to this rule is division by a constant power of two such as 16 256 512 etc Blu Logic recognizes this special situation and implements the division as a faster shift operation Division by a variable value such as a register or a subexpression involving a register will always be slow regardless of the value because Blu Logic cannot predict the value of the register in advance Analog Inputs and Outputs If your controller has analog input and or output points they will appear as registers in the IF tab of the Asset Palette and can be used in expressions Analog output points appear in the IF and REG tabs You can t set the value of an analog input so they do not appear under REG Analog I O points are commonly 10 or 12 bits This means the range of possible values is O to 1023 for a 10 bit point and O to 4095 for a 12 bit point A twelve bit zero to five volt input for example will have a value of O at O volts of 4095 at 5 volts and 2048 at 2 5 volts All Bld L
45. o or more together If wired as shown below output 2 of the Sequencer 29 Ver 22 Jan 2013 Blu Logic Language Details Extension will activate on the step after the last output of the upper sequencer Sequencer 32 IF and REG To load a value into any register whether it is a stand alone holding register part of a timer counter shift register or sequencer or associated with an analog output use a REG ladder element REG evaluates a formula explained below and sets the specified register to the result The assignment only happens if the logic input to the REG element is turned on The assignment occurs on every scan in which the input is energized That is it is not edge triggered Besides performing math a REG element can be used to add asynchronous resets additional count inputs and other advanced functions to timers and counters as mentioned in the Timers and Counters section To test a register value use an IF element Like REG an IF element includes a formula In this case the formula is evaluated when the element s logic input is on The result is compared to the value in the specified register If the comparison is logically true and the input to the element is on then the element s output will turn on Turning off the input will turn off the output regardless of the value in the register IF elements referenced to the TIM register of a timer can be used to create signals at intermediate times Capich
46. ogic registers are 32 bits but the unused bits of the register corresponding to an analog I O point will always be zero See the specifications for a specific controller model for the designations and ranges its analog I O points 32 Ver 22 Jan 2013 Bl Logic Language Details Modbus Communications If your custom Blu controller includes a Modbus serial port then it will respond to the Modbus RTU protocol to read and write relays and registers This facility is often used to allow other PLCs computer systems or Man Machine interfaces to interact with your controller The Modbus architecture supports two kinds of data bits called coils in Modbus terminology and relays elsewhere in this document for on off values and registers for numeric values In most small PLCs with Modbus support Modbus messages from the Modbus master device directly access the I O points and registers of the ladder diagram Bl Logic takes a different approach for several reasons Bl Logic provides dedicated Modbus bits and registers for the Modbus master device to access The ladder diagram can write values to registers or bits for the Modbus master to read or it can refer to Modbus registers and bits which are written by the master The Modbus master therefore can only access information that the ladder diagram is specifically intended to expose to the outside world Physical I O internal relays and registers cannot be affected by Modbus mess
47. ontrol over the wiring by doing it in segments Click and drag in either a purely horizontal or vertical direction and release Click drag and release to create the next segment and so on until you reach your destination Contacts in the left most column of the diagram and coils in the right most column will connect themselves to the vertical power supply rails Typically you should let the automatic connection router try first Most of the time it does a good job If you don t like the result type Ctrl Z to undo the connection Then manually wire the connection step by step With time you ll get a feel for when you can trust the automatic connection router and when it needs a little help The wire cutter tool is used to delete circuitry If you delete a wire segment or a circuit element all wiring connected to it will automatically be ripped out Holding down the SHIFT key as you click will temporarily disable auto rip up You can turn this feature off persistently in the Preferences dialog Look for it under the Edit menu Selection and Multi Cell Operations You can use the mouse to select a cell or a collection of cells of the diagram Left click a cell to select it Left click and drag to select a rectangular region Each time you click or click and drag the previous selection is lost To retain previous selections hold down the CTRL key as you click or click and drag In this way you can select any combination of cells The DEL or DELE
48. rams in one place The complete computer novice who probably isn t reading this may just keep them on the desktop Remember that there is no way to retrieve a downloaded program from the controller This is by design to deter reverse engineering of our customers products However it also means that you must be sure to keep track of the BLU file for each of your projects so that you can refer to it in the future To be doubly safe print out the diagram Under the Reports menu and archive the printout with other project documentation Selecting the Controller Model Blu Logic must know which model of Bl controller you need to develop a diagram for Whether it is a standard model or a custom design each Blu controller has a model number This is an 8 digit number in the form 9999 9999 You will find this number printed on the controller s printed circuit board Please take care to select the correct model so the program will present you with the matching feature set When you start Bl Logic for the first time it will display a dialog requesting the model number You can either type it in or you can connect the controllers USB port and the Controller Model Number q x Connect USB cable to automatically identify controller model Model Number 9807 0069 m E g 9999 9999 11 Ver 22 Jan 2013 Blu Logic Using Bl Logic software will interrogate the controller and fill in the model number for you Click OK
49. registers as needed The Asset Palette has a tab for each type of resource Contact Coil Timer Counter Shift Register Sequencer REG and IF Building the Diagram There are a couple of ways to lay down circuit elements to build your diagram The most obvious is to click on an asset in the Asset Palette and then click on the diagram to place an instance of it If you click on NEW RELAY NEW TIMER NEW COUNTER NEW REGISTER NEW SHIFT REG or NEW SEQUENCER a dialog will pop up for you to name and configure the new asset For each timer or counter you create a contact and two associated registers are also created The contact is named with the name of the timer and the suffix CON such as MyTimer CON A timer will have registers with suffixes TIM for the timer and PRE for the preset A counter will have CNT and PRE registers Timers Counters Shift Registers Sequencers and the REG element must be at the far right side of the diagram up against the neutral rail These blocks are like the motor part of the timer The contacts for each of these assets appear in the Asset Palette and are added to the diagram separately It is fairly common to have one of the contacts of a coil or counter wired to energize its own reset input Another common feedback circuit is to connect a shift register contact to its own data input so that the bit pattern constantly circulates 13 Ver 22 Jan 2013 Blu Logic Using Bl Logic Wh
50. rn terminals are often provided in the same connector or terminal block as the output terminals POWER SUPPLY CONTROLLER A sinking output requires a switch between the negative side of the load and the sink In Blu Logic controllers the negative side of the switch in a sinking output is connected to the negative power supply terminal within the controller CONTROLLER Inputs can also be sourcing or sinking A sourcing input has an internal path to the positive power supply terminal Thus to complete the circuit and turn on the input the external wiring needs to connect the input terminal of the controller to return A sinking input completes the path to the return or negative supply inside the controller To activate a sinking input the external wiring needs to connect the input terminal to the positive power supply POWER SUPPLY Sinking Input Sourcing Input K CONTROLLER CONTROLLER Don t read this paragraph if you re already confused The source may be negative and the sink positive and the terms would still be valid This alternate positive ground convention is rarely encountered in industrial automation or indeed most modern electronics It s rare enough that few explanations of the concepts of sourcing and sinking even mention it In this document we have assumed that the source is always the positive terminal of the power supply This nearly universal convention i
51. rom the source such as the positive terminal of a power supply or a battery to the sink In the case of the power supply or battery mentioned above the sink would be the negative terminal The negative terminal of the power supply in a control system is often called the return common or ground ground is the least correct of these terms but probably the most used Source SUPPLY Sink Consider the case of a controller output driving a load such as a lamp relay coil solenoid motor or maybe the input of another electronic device Inside the controller output is some kind of a switch usually a transistor sometimes an electromechanical relay The switch is opened to break the circuit when the load is to be turned off and the switch is closed to complete the circuit when the load is to be tuned on The switch could either be located between the power source 1 e the positive terminal of the power supply or between the load and the power sink The former case is referred to a sourcing output and the latter is called a sinking output POWER SUPPLY In the case of most Blu Logic controllers a sourcing output has the positive side of the switch connected to the positive terminal of the power supply inside of the controller Thus a load is connected between the output terminal and the return aka ground terminal of the power supply For convenience in wiring extra retu
52. s called negative ground Many industrial sensors such as photoelectric sensors proximity sensors temperature switches etc are referred to as either NPN or PNP This is because the outputs are often constructed with transistors and an NPN transistor is suitable for a sinking output where a PNP transistor is more suitable for a sourcing output All you really need to know is that PNP is another name for sourcing and NPN is another name for sinking One final note When you connect an output to an input they need to be of opposite types A sinking input is activated by a path to the positive supply Thus a sinking input can be driven by a sourcing output A PNP sensor has a sourcing output so it would be connected to a sinking input on a controller If you connect a sinking output to a sinking input you will form a complete circuit from the return back to the return again There is no power source in the circuit so no current will flow and the input will not be activated Analogously a sourcing input would need to be driven by a sinking output
53. set input or load some other non zero value into the register with a REG element Although the Up and Down count inputs of counters are only sensitive to rising edges the RESET input of an Up Counter and the PRESET input of a Down Counter constantly respond to the state of the input If you hold RESET active the counter register will stay at zero even if there are also pulses on the count input An Up Down Counter has the same behavior as an Up counter but has an additional input that makes it count down The behavior of the contacts is the same as the Up 27 Ver 22 Jan 2013 Bl Logic Language Details Counter The contacts are closed when the count register reaches the preset The Reset input to an Up Down counter sets it to zero Sometimes you need a contact which closes when the Up Down counter is at zero as well as a contact for the preset You can use an IF element to create an auxiliary contact for any timer or counter In this case you would use IF MyUpDownCounter CNT 0 Another way to directly manipulate a counter s CNT register is with a REG element You can use REG to preset a counter to any value at any time If that value is greater than or equal to the counter s preset then the counter s contacts will close Modifying a counter s CNT register with a REG does not instantly change the contacts but the contacts will update to be consistent with the new register value the next time the rung containing the actual cou
54. start the program Ver 22 Jan 2013 Blu Logic Introduction to Ladder Logic Installation Selecting the Controller Model Assets and the Asset Palette Building the Diagram Wiring Connections Selection and Multi Cell Operations Copy Cut and Paste Insert and Delete Rungs Reconfiguring Assets Clip Leads and Lockout Tags Downloading to a Blu Logic Controller Reports Print Diagram Index Asset List Troubleshooting Language Details Contacts and Coils Rung Execution Order Timers and Counters Shift Registers Sequencers Table of Contents 11 11 13 13 14 15 15 15 16 17 18 19 19 19 19 19 21 21 23 24 28 29 Ver 22 Jan 2013 Blu Logic IF and REG Mathematical Expressions Formulae Operators in Precedence Order Analog Inputs and Outputs Modbus Communications Controller Startup Integer Math Blu Logic Elements Contacts Coils Timers Counters Special and Shortcut Keys Execution Time of Operations and Elements Table of Contents 30 31 31 32 33 35 37 41 41 41 42 42 43 45 Ver 22 Jan 2013 Blu Logic Intro to Ladder Logic Introduction to Ladder Logic You may want to skip this section if you have used ladder logic before This introduction is intended for the new user If so you ll find the next section on page 11 A ladder diagram is a kind of electrical circuit diagram It looks like a ladder There are two long vertical lines one on either side repr
55. ters and embedded peripherals The available operators are addition subtraction multiplication division and modulus plus boolean operators for AND OR and XOR The register to which the result is transferred can be an internal register or can be the timer or preset of a timer or the counter or preset of a counter REG is a very powerful tool A register can be assigned with the result of a formula involving itself A counter could be implemented by a REG rung like MyCounter MyCounter 1 A REG element has an input and the assignment operation occurs on each scan in which this input is on An IF element compares a register either a pure working register one of the registers of a timer or counter or an analog input The number in the register is compared to the result of a formula Any of the usual compare operators can be used lt gt lt or gt The formula can combine constants and other register values including the registers in timers counters and analog inputs and outputs The available operators are addition subtraction multiplication division and modulus The output of an IF element is energized if the input is energized and if the result of the comparison is true The IF formula does not support logical operators such as AND and OR but these are easily implemented by combining multiple IF rungs in the ladder diagram Special and Shortcut Keys ESC ARROWS The Escape key clears the current tool If no tool
56. unit of the timebase A Millisecond timer running for 10 seconds will reach a value of 10 000 Timers are guaranteed not to tick between scans The value of a timer changes only when the rung containing the timer is scanned unless another rung modifies it directly with a REG element If the scan time is more than a millisecond millisecond timers can advance by more than one count at a time to keep up For this reason be careful about comparing the TIM register of a fast timer for equality to single value It may skip that value Use greater than or less than comparisons to know when a timer passes a certain point The four timebases are global to the system and are not synchronized to the input of a particular timer element That is an Hour timebase timer with a preset of 10 will expire in 10 hours only if it is started at an exact hour anniversary of power up of the controller If started at an asynchronous time it could expire any time between 9 and 10 real time hours of the input turning on Note that because the registers are 32 bits the available range of values lets you preset a millisecond timer to run for days or a second timer to run for decades So if you need a minute or hour timer with tighter synchronization you can probably use a second timer instead If you absolutely have to have something like an hour timer synchronized to the start of the timer use a second or millisecond timer to create your own one hour timebase
57. uns when the input is energized and stops when the input is de energized Unlike On and Off Delay timers the value in the stopwatch timer s register is retained between changes in the input state The timer keeps track of the accumulated time that the input is energized no matter how much it switches off and on in the meantime When the preset is reached the timer s contacts close and the timer freezes Because the register does not automatically reset a Stopwatch timer also has a Reset input When this input is energized the timer resets to zero If one of the timer s own contacts is fed back to the reset input the timer will reset to zero when it reaches the preset but all contacts will close for a single scan of the ladder That is they will pulse Any timer or counter can be reset to zero using a REG rung in the form A REG rung can be used to preset a timer or counter to any value at any time A REG rung can also modify the preset MyTimer PRE of a timer or counter Complex behaviors can be implemented using this technique For example a ten second snooze input could be added to a timer with a rung like this When a timer runs it ticks at an one of four rates Milliseconds Seconds Minutes or Hours The rate is chosen when the timer is created and cannot be changed by the 25 Ver 22 Jan 2013 Bl Logic Language Details ladder diagram The value in the timer s registers represents elapsed time in the
58. utomation actually do have experience with conventional text based computer languages but Ladder Logic has other advantages and is still widely used in automation At the time virtually all interaction with computers was textual and with a fixed width font at that Graphics were rare low resolution and slow A lot of modern ladder logic programs including Blu Logic use graphics to display the diagrams but the language was originally designed so that the diagrams could be drawn with standard text symbols 5 Ver 30 Jan 2012 Blu Logic Intro to Ladder Logic For example here is a single rung of ladder logic The vertical line on the left side is the hot rail The vertical line on the right is the neutral rail An imaginary voltage is present between these rails The element labeled A on the left is a contact In this case it is a Normally Open NO contact The connection is broken until a corresponding coil or physical input turns on Then the contact closes and current can flow through it energizing elements wired to its output on the right side The element labeled X on the right side of the diagram is a coil In this simple diagram when the contact is closed the coil will be energized The coil can either operate other contacts in the diagram a so called internal relay or can operate an external circuit in the real world There are other forms of both contacts and coils The Normally
59. want the wizard to do Install the software automatically Recommended Install from a list or specific location Advanced lt ick Next to continue CR lt Back Next gt Cancel You will probably have to repeat this process if you later use a different USB port or if you otherwise re arrange your USB network Once your controller is connected and the driver is associated if required you are ready to download your diagram Under the Tools menu choose Download Bl Logic will do some error checking of your program and if all is well will send it to your controller If already connected to power the controller will start scanning the diagram as soon as the USB cable is disconnected lf Bl Logic finds problems with your diagram a new window will pop up with a list of error messages Click on an error message to quickly find that part of your diagram You can close the error message window by clicking the X at the right side of the title bar 18 Ver 22 Jan 2013 Blu Logic Using Bl Logic You can run the download error check by itself to make sure that the download will succeed You do not need a controller connected to do this This function is called Error Check and it s also in the Tools menu To avoid confusing the program do not connect more than one controller at a time to your PC If you do the program will only download to one of the connected controllers but which one
60. y cell in the diagram It will turn dark to indicate that it is selected You can drive this selection around the diagram with the keyboard arrows If you click an item from the Asset Palette when you have a single empty cell selected an instance of that asset will be placed in the empty cell and the selection cursor will move to the right ready for the next element You can also configure the program to put a single cell wide wire between each element placed in this way which facilitates making vertical connections later If you need to change the type of a contact or coil for example from NO to NC use the left arrow to move back to it hit the space bar to change it and then hit the right arrow to go back to the next empty space You can think of the two methods as either clicking in the palette first and then on the diagram or clicking on the diagram first and then the palette The former seems to be more natural but the latter method requires less movement of the mouse overall Wiring Connections The screwdriver is used to make connections Click the screwdriver in the Toolbox and your cursor will change to a screwdriver Click on either free end of a coil contact or other element Holding the left mouse button down drag the cursor to the other end of the desired connection When you release the button the program will attempt to wire 14 Ver 22 Jan 2013 Blu Logic Using Bl Logic your two points together You can exercise more c
61. ys would work In practice since the CPU inside your Blu controller is a sequential machine ladder diagrams are executed sequentially and the practical ladder programmer is aware of this fact and depends on it One pass through the diagram top rung to bottom is called a scan One of the important specifications of a controller is its scan time because this determines how quickly the diagram can respond to events Scan times of modern controllers are typically a few tens of milliseconds Controllers based on Blu Logic are extremely fast Scan times for small or medium sized programs are rarely more than one millisecond In fact the scan time is so fast that your diagram may react to contact bounce of mechanical switch contacts as if the switch was operated more than once It is a good idea to design logic so that additional activations of a given contact do not matter but this is not always possible If contact bounce is a problem in your application use an off delay timer to de bounce the contact It is generally considered safe to assume that the rungs of the diagram are processed in order from the top to the bottom of the diagram However it is risky to make any particular assumption about the order of execution of elements within a single rung Real world ladder diagrams comprise hundreds even thousands of rungs As such they can implement remarkably sophisticated behavior and control large and complex machines production li
62. ysical discrete output an internal relay or a discrete input to a built in peripheral If this coil is present on a relay which also has SET RESET or TOGGLE coils unexpected behavior may result SET coil A true signal to this coil latches the relay on It will stay on until a RESET or TOGGLE coil with the same name is activated RESET coil A true signal to this coil latches the relay off 41 Ver 22 Jan 2013 Blu Logic PE San Timers On Delay Off Delay Stopwatch Timer Counters Up Counter Down Counter Up Down Counter Reference TOGGLE coil On the rising edge of a true signal to this coil the relay will change state An On Delay timer starts running when the input becomes true When the time reaches the preset the output comes on The output stays on until the input goes false again If the input goes false before the timer reaches the preset it stops and is reset back to zero immediately The timer register and the preset value can be manipulated by REG rungs An Off Delay turns on its output when its input becomes true When the input goes false again the output stays on The timer starts running When the preset is reached the timer output turns off A Stopwatch Timer also called a Retentive Timer runs when its input is on and freezes when the input is false Unlike the other timers it does not reset when the input turns off The Stopwatch Timer output comes on when the preset is

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