Chapter 9 - AutomationDirect
Contents
1. er You may not get the busy display BUSY if the program is not very long One of two displays will appear Error Display example 00050 E401 MISSING END shows location in question Syr OR display GSYNTAX ERROR 2 See the Error Codes Section for a complete listing of programming error codes If you get an error just press CLR and the Handheld will display the instruction where the error occurred Correct the problem and continue running the Syntax check until the NO SYNTAX ERROR message appears DL05 Micro PLC User Manual 6th Edition Rev C Q ll Chapter 9 Maintenance and Troubleshooting i Special Instructions There are several instructions that can be used to help you debug your program during machine startup operations END PAUSE STOP END Instruction If you need a way to quickly disable part of the program just insert an END statement prior to the portion that should be disabled When the CPU encounters the END statement it assumes that is the end of the program The following diagram shows an example Normal Program New END disables X10 and Y1 X0 x2 d XO X2 de M V X1 X3 X4 X1 X3 X4 i 1 1 X10 y1 X10 1 Y EJ exo HI C2 GD PAUSE Instruction This instruction provides a quick way to allow the inputs or other logic to operate while disabling selected outputs The output image registe2. Missing FOR Missing T C Missing NEXT Bad TMRA Missing IRT Bad CNT SBR LBL gt 64 Bad SR Duplicate stage reference Stack Overflow Duplicate SBR LBL reference Stack Underflow HP Peripheral port time out Logic Error Invalid ISG SG address Missing Circuit Invalid ISG SG address Duplicate coil reference Invalid RTC Duplicate TMR reference Invalid RT Duplicate CNT reference Invalid INT address Invalid IRTC DL05 Micro PLC User Manual 6th Edition Rev C l 9 5 Print instruction Chapter 9 Maintenance and Troubleshooting CPU Indicators The DL05 Micro PLCs have indicators on the front to help you determine potential problems with the system In normal runtime operation only the RUN and PWR indicators are on The table below is a quick reference to potential problems Indicator Status Potential Problems 1 System voltage incorrect 2 PLC power supply faulty 1 CPU programming error 2 CPU in program mode RUN LED blinking A firmware upgrade is needed 1 Electrical noise interference 2 Internal CPU defective PWR LED off RUN LED off CPU LED on PWR Indicator In general there are three reasons for the CPU power status LED PWR to be OFF EJ 1 Power to the unit is incorrect or is not applied 2 PLC power supply is faulty 3 Other component s have the power supply shut down If
3. the voltage to the power supply is not correct the PLC may not operate properly or may not operate at all Use the following guidelines to correct the problem WARNING To minimize the risk of electrical shock always disconnect the system power before inspecting the physical wiring 1 First disconnect the external power 2 Verify that all external circuit breakers or fuses are still intact 3 Check all incoming wiring for loose connections If you re using a separate termination block check those connections for accuracy and integrity If the connections are acceptable reconnect the system power and verify the voltage at the DL05 power input is within specification If the voltage is not correct shut down the system and correct the problem 5 If all wiring is connected correctly and the incoming power is within the specifications the PLC internal supply may be faulty The best way to check for a faulty PLC is to substitute a known good one to see if this corrects the problem The removable connectors on the DL05 make this relatively easy If there has been a major power surge it is possible the PLC internal power supply has been damaged If you suspect this is the cause of the power supply damage consider installing an AC line conditioner to attenuate damaging voltage spikes in the future NOTE See Chapter 2 for suppressing the DLO5 outputs 9 6 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 9 Maintenance and T
4. to make changes to the application program during Run Mode These edits are not bumpless Instead CPU scan is momentarily interrupted and the outputs are maintained in their current state until the program change is complete This means if the output is off it will remain off until the program change is complete If the output is on it will remain on 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 There are some important operational changes during Run Time Edits 1 If there is a syntax error in the new instruction the CPU will not enter the Run Mode 2 If you delete an output coil reference and the output was on at the time the output will remain on until it is forced off with a programming device 3 Input point changes are not acknowledged during Run Time Edits so if you re using a high speed operation and a critical input comes on the CPU may not see the change Not all instructions can be edited during a Run Time Edit session The following list shows the instructions that can be edited Mnemonic Description Mnemonic Description Timer Or greater than or equal or less than Fast timer Load data constant Accumulating timer Load data double constant Accumulatin
5. MAINTENANCE AND APTER TROUBLESHOOTING In This Chapter Hardware System Maintenance eese 9 2 Bic AP 9 2 CPU Indicators aad dc RUEUROr RECO EORR ERA EE ER en 9 6 Communications Problems ucc gt FX DE dp EE eee 9 7 I O Point Troubleshooting scu rm e REI en 9 8 Noise Troubleshooting 33 43 4 Jed once OF oe e RC eds 9 10 Machine Startup and Program Troubleshooting 9 11 Chapter 9 Maintenance and Troubleshooting M Hardware System Maintenance Standard Maintenance No regular or preventative maintenance is required for this product there are no internal batteries however a routine maintenance check about every one or two months of your PLC and control system is good practice and should include the following items Air Temperature Check the air temperature in the control cabinet so the operating temperature range of any component is not exceeded Air Filter If the control cabinet has an air filter clean or replace it periodically as required Fuses or breakers Verify that all fuses and breakers are intact Cleaning the Unit Check that all air vents are clear If the exterior case needs cleaning disconnect the input power and carefully wipe the case using a damp cloth Do not let water enter the case through the air vents and do not use strong detergents because this may discolor the case Diagnostics Diagnostics Your DL05 Micro PLC perf
6. ations Problems If you cannot establish communications with the CPU check for these problems The cable is disconnected The cable has a broken wire or has been wired incorrectly The cable is improperly terminated or grounded The device connected is not operating at the correct baud rate 9600 baud The device connected to the port is sending data incorrectly A grounding difference exists between the two devices Electrical noise is causing intermittent errors The PLC has a bad communication port and should be replaced For problems in communicating with DirectSOFT 5 on a personal computer refer to the DirectSOFT 5 manual It includes a troubleshooting section that can help you diagnose PC problems in communications port setup address or interrupt conflicts etc DL05 Micro PLC User Manual 6th Edition Rev C l 9 7 Chapter 9 Maintenance and Troubleshooting Bi M 1 0 Point Troubleshooting Possible Causes If you suspect an I O error there are several things that could be causing the problem High Speed I O configuration error e A blown fuse in your machine or panel the DL05 does not have internal I O fuses A loose terminal block The auxiliary 24 VDC supply has failed The Input or Output Circuit has failed Some Quick Steps When troubleshooting the DL05 Micro PLCs there are a few facts you should be aware of These facts may assist you in quickly correcting an I O problem HSIO
7. ccurred STOP instruction was executed Half carry occurred Interrupt enabled Carry occurred System Monitoring Relays Result is negative sign Override setup Pointer reference error Scan control error Overflow Critical error Data is not in BCD Non critical error Diagnostics error Program memory error 1 0 error Communications error Fault instruction was executed Watchdog timeout Syntax error Cannot solve the logic Communication error Table instruction overrun Load zero DL05 Micro PLC User Manual 6th Edition Rev C 9 3 Chapter 9 Maintenance and Troubleshooting i M DLO05 Micro PLC Error Codes These errors can be generated by the CPU or by the Handheld Programmer depending on the actual error Appendix B provides a more complete description of the error codes The errors can be detected at various times However most of them are detected at power up on entry to Run Mode or when a Handheld Programmer key sequence results in an error or an illegal request Error Code Description Error Code Description Software time out Unit is offline Invalid instruction RAM parity error in the CPU Unit is online Write failed CPU mode Invalid command CPU locked Communications error 1 Wrong password Communications error 2 Password reset Communications error 3 Communicat
8. configuration errors are commonly mistaken for I O point failure during program development If the I O point in question is in XO X2 or YO Y1 check all parameter locations listed in Chapter 3 that apply to the HSIO mode you have selected The output circuits cannot detect shorted or open output points If you suspect one or more faulty points measure the voltage drop from the common to the suspect point Remember when using a EJ Digital Volt Meter leakage current from an output device such as a triac or a transistor must be considered A point which is off may appear to be on if no load is connected the point The I O point status indicators are logic side indicators This means the LED which indicates the on or off status reflects the status of the point with respect to the CPU On an output point the status indicators could be operating normally while the actual output device transistor triac etc could be damaged With an input point if the indicator LED is on the input circuitry is probably operating properly Verify the LED goes off when the input signal is removed Leakage current can be a problem when connecting field devices to an I O point False input signals can be generated when the leakage current of an output device is great enough to turn on the connected input device To correct this install a resistor in parallel with the input or output of the circuit The value of this resistor will depend on the amount of leakage curr
9. e Check You can also check for multiple uses of the same output coil Both programming devices offer a way to check for this condition For example you can AUX 21 CHECK PROGRAM to check for duplicate references from a Handheld Programmer or you can use the PLC Diagnostics menu option within DirectSOFT 5 The following example shows how to perform the duplicate reference check with a Handheld Programmer Use AUX 21 to perform syntax check C B CLR 2 1 AUX ENT Select duplicate reference check very long One of two displays will appear Error Display example shows location in question Syntax OK display AUX 21 CHECK PRO 1 SYN 2 DUP REF xr You may not get the busy BUSY display if the program is not 00024 E471 DUP COIL REF NO DUP REFS If you get an error just press CLR and the Handheld will display the instruction where the error occurred Correct the problem and continue running the Duplicate Reference check until no duplicate references are found though they are acceptable NOTE You can use the same coil in more than one location especially in programs containing Stage instructions and or OROUT instructions The Duplicate Reference check will find occurrences even DL05 Micro PLC User Manual 6th Edition Rev C 9 13 Chapter 9 Maintenance and Troubleshooting Run Time Edits The DLO5 Micro PLC allows you
10. ent and the voltage applied but usually a 10K to 20K resistor will work Verify the wattage rating of the resistor is correct for your application Because of the removable terminal blocks on the DL05 the easiest method to determine if an I O circuit has failed is to replace the unit if you have a spare However if you suspect a field device is defective that device may cause the same failure in the replacement PLC as well As a point of caution you may want to check devices or power supplies connected to the failed I O circuit before replacing the unit with a spare 9 8 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 9 Maintenance and Troubleshooting Itl Output points can be set on or off in the DL05 series CPUs If you want to do an I O check out independent of the application program follow the procedure below Action Use a handheld programmer or DireciSOFT to communicate online to the PLC Change to Program Mode Go to address 0 Insert an END statement at address 0 This will cause program execution to occur only at address 0 and prevent the application program from turning the 1 0 points on or off Change to Run Mode Use the programming device to set turn on or off the points you wish to test When you finish testing 1 0 points delete the END statement at address 0 operation that can result in a risk of personal injury or eq
11. g fast timer Add data double constant Counter Subtract data double constant Up Down counter Multiply constant Stage counter Divide constant Store Store not Compare accumulator constant And And not And accumulator constant Or Or not Or accumulator constant Store equal Store not equal Exclusive or accumulator constant And equal And not equal Load discrete points to accumulator Or equal Or not equal Output accumulator to discrete points Store greater than or equal Shift accumulator right Store less than Shift accumulator left NE an ter than or equal Numeric constant 9 14 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 9 Maintenance and Troubleshooting Kr Well use the program logic shown to describe how this process works In the example we ll n xl Yo change X0 to C10 Note the example assumes you have already placed the CPU in Run Mode Use the MODE key to select Run Time Edits MODE CHANGE RUN TIME EDIT MODE NEXT NEXT ENT Press ENT to confirm the Run Time Edits CO mm Note the RUN LED on the D2 HPP NAODE CHANGE Handheld starts flashing to indicate RUNTIME EDITS Run T ime Edits are enabled Find the instruction you want to change X0 SHFT x A surr FD REF E I 00000 STR XO 9 Press the a
12. ions error 6 Time out Communications error Memory full Instruction missing Reference missing Out of memory EEPROM Memory not blank No Handheld Programmer EEPROM V memory only HP Peripheral port time out Bad entry Bad address Bad command Bad reference value Program only Invalid instruction Bad viite operation Invalid operation Memory type error should be EEPROM Bad operation CPU in Run Mis compare Bad operation CPU in Test Run Handheld Programmer system error Bad operation CPU in Test Program Handheld Programmer ROM error Bad operation CPU in Program Handheld Programmer RAM error Mode Switch not in Term position 9Q9 4 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 9 Maintenance and Troubleshooting E EK Program Error Codes The following table lists program syntax and runtime error codes Error detection occurs during a Program to Run mode transition or when you use AUX 21 Check Program The CPU will also turn on SP52 and store the error code in V7755 Appendix B provides a more complete description of the error codes Error Code Description Error Code Description No Program in CPU Invalid IRT address Missing END statement Invalid Data Address Missing LBL ACON NCON Missing RET Bad MLS MLR
13. oint The example assumes you have already placed the CPU into Run Mode 9 From a clear display use the following keystrokes 16P STATUS BIT REF X STAT ENT Use the PREV or NEXT keys to select the Y data type Once the Y appears press 0 to start at YO Y10 YO uggponpnagangpnnmnan NEXT Use arrow keys to select point then use ON and OFF to change the status Y2 is now on Y 10 YO upnuugugounguuunuumwudu ON c c SHFT NS Bit Forcing with Direct Access From a blank display use the following keystrokes to force Y7 ON Solid fill indicates point is on seet Yang suT ON BIT FORCE Y7 a From a blank display use the following keystrokes to force Y7 OFF No fill indicates point is off srt Yas 7 suet OFF BIT FORCE Y7 H 9 16 DL05 Micro PLC User Manual 6th Edition Rev C
14. olation transformer for all AC sources can correct this problem DC sources should be well grounded good quality supplies Separate input wiring from output wiring Never run low voltage I O wiring close to high voltage wiring 9 10 DL05 Micro PLC User Manual 6th Edition Rev C Chapter 9 Maintenance and Troubleshooting M Kl Machine Startup and Program Troubleshooting The DLO05 Micro PLCs provide several features that can help you debug your program before and during machine startup This section discusses the following topics which can be very helpful Program Syntax Check Duplicate Reference Check Special Instructions Run Time Edits Forcing I O Points Syntax Check Even though the Handheld Programmer and DirectSOFT 5 provide error checking during program entry you may want to check a program that has been modified Both programming devices offer a way to check the program syntax For example you can use AUX 21 CHECK PROGRAM to check the program syntax from a Handheld Programmer or you can use the PLC Diagnostics menu option within DirectSOFT 5 This check will find a wide variety of programming errors The following example shows how to use the syntax check with a Handheld Programmer Use AUX 21 to perform syntax check 9 AUX 21 CHECK PRO C B 2 1 AUX ENT 1 SYN 2 DUP REF Select syntax check default selection
15. orms many pre defined diagnostic routines with every CPU scan E The diagnostics can detect various errors or failures in the PLC The two primary error classes are fatal and non fatal Fatal Errors Fatal errors are errors which may cause the system to function improperly perhaps introducing a safety problem The CPU will automatically switch to Program Mode if it is in Run Mode Remember in Program Mode all outputs are turned off If the fatal error is detected while the CPU is in Program Mode the CPU will not allow you to transition to Run Mode until the error has been corrected Some examples of fatal errors are Power supply failure Parity error or CPU malfunction Particular programming errors Non fatal Errors Non fatal errors are errors that need your attention but should not cause improper operation They do not cause or prevent any mode transitions of the CPU The application program can use special relay contacts to detect non fatal errors and even take the system to an orderly shutdown or switch the CPU to Program Mode if desired An example of a non fatal error is Particular programming errors The programming devices will notify you of an error if one occurs while online DirectSOFT 5 provides the error number and an error message The handheld programmer displays error numbers and short descriptions of the error Appendix B has a complete list of error messages in order by error number Many error message
16. r is still updated but the output circuits are not For example you could make this conditional by adding an input contact or CR to control the instruction with a switch or a programming device Or you could just add the instruction without any conditions so the selected outputs would be disabled at all times Normal Program PAUSE disables YO and Y1 XO x2 YO E C P muere Pause X1 X3 X4 XO x2 po X10 Y1 X1 x3 X4 n 2 1 1 z X10 i eno V Gs STOP Instruction Sometimes during machine startup you need a way to quickly turn off all the outputs and return to Program Mode You can use the STOP instruction When this instruction is executed the CPU automatically exits Run Mode and enters Program Mode Remember all outputs are turned off during Program Mode The following diagram shows an example of a condition that returns the CPU to Program Mode 9 12 DL05 Micro PLC User Manual 6th Edition Rev C Normal Program Chapter 9 Maintenance and Troubleshooting nS STOP puts CPU in Program Mode XO X2 YO X7 E Go X1 x3 X4 XO X2 YO 1 1 X5 Y1 X1 X3 X4 f b d 1 1 Z X5 zu exo V 2 GD In the example shown above you could trigger X7 which would execute the STOP instruction The CPU would enter Program Mode and all outputs would be turned off Duplicate Referenc
17. roubleshooting E Kr RUN Indicator If the CPU will not enter the Run mode the RUN indicator is off the problem is usually in the application program unless the CPU has a fatal error If a fatal error has occurred the CPU LED should be on You can use a programming device to determine the cause of the error The RUN indicator is blinking the PLC firmware needs to be upgraded Both of the programming devices Handheld Programmer and DirectSOFT 5 will return an error message describing the problem Depending on the error there may also be an AUX function you can use to help diagnose the problem The most common programming error is Missing END Statement All application programs require an END statement for proper termination A complete list of error codes can be found in Appendix B CPU Indicator If the CPU indicator is on a fatal error has occurred in the CPU Generally this is not a programming problem but an actual hardware failure You can power cycle the system to clear the error If the error clears you should monitor the system and determine what caused the problem You will find this problem is sometimes caused by high frequency electrical noise introduced into the CPU from an outside source Check your system grounding and install electrical noise filters if the grounding is suspected If power cycling the system does not reset the error or if the problem returns you should replace the CPU 9 Communic
18. rrow key to move to the X Then enter the new contact C10 RUNTIME EDIT gt gt SHFT i B ENT SIR C10 Press ENT to confirm the change mr Note once you press ENT the next address is displayed OR CO DL05 Micro PLC User Manual 6th Edition Rev C 9 15 Chapter 9 Maintenance and Troubleshooting Forcing I O Points There are many times especially during machine startup and troubleshooting that you need the capability to force an I O point to be either on or off Before you use a programming device to force any data type it is important you understand how the DLO5 CPUs process the forcing requests WARNING Only authorized personnel fully familiar with the application should make program changes Do thoroughly consider the impact of any changes to minimize the risk of personal injury or damage to equipment Bit Forcing Bit forcing temporarily changes the status of a discrete bit For example you may want to force an input on even though the program has turned it off This allows you to change the point status stored in the image register The forced value will be valid until the CPU writes to the image register location during the next scan This is useful you just need to force a bit on to trigger another event Xo Yo The following diagrams show a brief example of how our you could use the D2 HPP Handheld Programmer to force an I O p
19. s point to supplemental V memory locations which contain related information Special relays SP contacts also provide error indications 9 2 DLO05 Micro PLC User Manual 6th Edition Rev C Chapter 9 Maintenance and Troubleshooting V memory Error Code Locations i The following table names the specific memory locations that correspond to certain types of error messages Error Class Error Category Diagnostic V memory User Defined Error code used with FAULT instruction V7751 System Error Fatal Error code V7755 ajor Error code V7756 inor Error code V7757 Grammatical Address where syntax error occurs V7763 Error Code found during syntax check V7764 CPU Scan Number of scans since last Program to Run Mode transition V7765 Current scan time ms V7775 inimum scan time ms V7776 aximum scan time ms V7777 Special Relays SP Corresponding to Error Codes The special relay table also includes status indicators which can indicate errors For a more detailed description of each of these special relays refer to Appendix D CPU Status Relays Accumulator Status Relays Forced Run mode Acc is less than value Terminal Run mode Acc is equal to value Test Run mode Acc is greater than value Test stop mode Acc result is zero Terminal Program mode Half borrow occurred Forced stop Borrow o
20. the corrective actions for either of the types of noise problems are similar Conducted noise is when the electrical interference is introduced into the system by way of a attached wire panel connection etc It may enter through an I O circuit a power supply connection the communication ground connection or the chassis ground connection Radiated noise is when the electrical interference is introduced into the system without a direct electrical connection much in the same manner as radio waves Reducing Electrical Noise While electrical noise cannot be eliminated it can be reduced to a level that will not affect the system Most noise problems result from improper grounding of the system A good earth ground can be the single most effective way to correct noise problems If a ground is not available install a ground rod as close to the system as possible Ensure all ground wires are single point grounds and are not daisy chained from one device to another Ground metal enclosures around the system A loose wire can act as a large antenna introducing noise into the system Therefore tighten all connections in your system Loose ground wires are more susceptible to noise than the other wires in your system Review Chapter 2 Installation Wiring and Specifications if you have questions regarding how to ground your system Electrical noise can enter the system through the power source for the PLC and I O circuits Installing an is
21. uipment damage Make sure you have 1 WARNING Depending on your application forcing 1 0 points may cause unpredictable machine taken all appropriate safety precautions prior to testing any 1 0 points Handheld Programmer Keystrokes Used to Test an Output Point x eno ee XO x2 x5 Az cA Insert an END statement D 1 1 dM M at the beginning of the X1 X3 X4 program This disables the remainder of the program GD From a clear display use the following keystrokes 16P STATUS STAT ENT BIT REF X Use the PREV or NEXT keys to select the Y data type 7 Y10 YO ENT NEXT Use arrow keys to select point then use Y2 is now on ON and OFF to change the status a lt SHFT ae Y 10 YO DL05 Micro PLC User Manual 6th Edition Rev C 9 9 Chapter 9 Maintenance and Troubleshooting i M Noise Troubleshooting Electrical Noise Problems Noise is one of the most difficult problems to diagnose Electrical noise can enter a system in many different ways and they fall into one of two categories conducted or radiated It may be difficult to determine how the noise is entering the system but
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