Chapter 9 - AutomationDirect
Contents
1. Chapter 9 Maintenance and Troubleshooting PWR Indicator There are four general reasons for the CPU power status LED PWR to be OFF 1 Power to the base is incorrect or is not applied 2 Base power supply is faulty 3 Other component s have the power supply shut down 4 Power budget for the base has been exceeded Incorrect Base Power If the voltage to the power supply is not correct the CPU and or base 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 system power and check all incoming wiring for loose connections 2 If you are using a separate termination panel check those connections to make sure the wiring is connected to the proper location 3 If the connections are acceptable reconnect the system power and measure the voltage at the base terminal strip to insure it is within specification If the voltage is not correct shut down the system and correct the problem If all wiring is connected correctly and the incoming power is within the specifications required the base power supply should be returned for repair Faulty CPU There is not a good check to test for a faulty CPU other than substituting a known good one to see if this corrects the problem If you have experienced major power2. Communication error Slot 7 DL205 User Manual 4th Edition Rev B l 9 5 Chapter 9 Maintenance and Troubleshooting m I O Module Codes Each system component has a code identifier This code identifier is used in some of the error messages related to the I O modules The following table shows these codes Component Type Component Type CPU Analog Input 1 0 Base 16 pt Input 8 pt Output Analog Output 8 pt Input Analog 1 0 Combo 4 input output Counter Interface combination Abnormal 12 pt Output No module detected 16 pt Output 32 pt Input 32 pt Output D2 DCM H2 ECOM F2 CP128 H2 ERM 100 H2 CTRIO 2 D2 RMSM The following diagram shows an example of how the I O module codes are used 2 r i r ofofofo o a0 ri ri E 2 2 eS Program Control Information V7752 V7753 V7754 V7755 SP47 0020 Desired module ID code 0026 Current module ID code 0002 Location of conflict 0252 Fatal error code 4 I O Configuration Error 9 6 DL205 User Manual 4th Edition Rev B E252 NEW I O CFG Chapter 9 Maintenance and Troubleshooting Error Message Tables The DL240 250 1 260 CPUs will automatically log any system error codes and any custom zap messages you have created in your app
3. Use arrow keys to select point then use yes now an ON and OFF to change the status amp amp sur oN Y10Y 0 16 l DL205 User Manual 4th Edition Rev B Chapter 9 Maintenance and Troubleshooting 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 falls into one of two categories conducted or radiated It may be difficult to determine how the noise is entering the system but the corrective actions for either of the types of noise problems are similar e Conducted noise is when the electrical interference is introduced into the system by way of an attached wire panel connection etc It may enter through an I O module a power supply connection the communication ground connection or the chassis ground connection e 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 e 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 Ifa ground is not avail
4. Shift accumulator left the instructions that can be edited 9 24 DL205 User Manual 4th Edition Rev B Numeric constant Chapter 9 Maintenance and Troubleshooting Use the program logic shown to describe how this process works In the example change XO to xo Ja P our C10 Note the example assumes you have already placed the CPU in Run Mode co Use the MODE key to select Run Time Edits MODE NEXT NEXT ENT MODE CHANGE RUN TIME EDIT Press ENT to confirm the Run Time Edits Note the RUN LED on the DL205 MODE CHANGE Handheld starts flashing to indicate RUNTIME EDITS Run Time Edits are enabled Find the instruction you want to change X0 9 SHFT X A SHFT FD REF L 00000 STR XO Press the arrow key to move to the X Then enter the new contact C10 RUNTIME EDIT gt gt suet C B A ENT ay STR C10 Press ENT to confirm the change enr Note once you press ENT the next address is displayed OR CO ENT DL205 User Manual 4th Edition Rev B 9 25 Chapter 9 Maintenance and Troubleshooting E Forcing I O Points There are many times especially during machine startup and troubleshooting where 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 dat
5. BIT FORCE Y10 L OUT Chapter 9 Maintenance and Troubleshooting Bit Override Forcing 3 230 V 240 V 250 1 V 260 Bit Override Indicators From a Clear display use the following keystrokes to turn on the override bit for Y10 Solid fill indicates point is on x SET gt SHFT ON INS BIT FORCE SET Y 10 Small box indicates override bit is on NOTE At this point you can use the PREV and NEXT keys to move to adjacent memory locations and use the SHFT ON keys to set the override bit on From a clear display use the following keystrokes to turn off the override bit for Y10 Solid fill indicates point is on 2 RST gt B 1 A 0 SHFT ON INS BIT FORCE RST Y 10 Small box is not present when override bit is off Like the example above you can use the PREV and NEXT keys to move to adjacent memory locations and use the SHFT OFF keys to set the override bit off Override bit indicators are also shown on the handheld programmer status display Below are the keystrokes to call the status display for Y10 Y20 From a clear display use the following keystrokes to display the status of Y10 Y20 STAT ENT NEXT B 1 A 0 ENT Override bit is on Point is on
6. GO TO T RUN MODE MODE NEXT ENT Press ENT to confirm TEST RUN Mode Note the TEST LED on the DL205 MODE CHANGE Handheld indicates the CPU is in CPU T RUN TEST Mode You can return to Run Mode enter Program Mode or enter TEST PGM Mode by using the Mode Key MODE CHANGE GO TO T PGM MODE CLR MODE NEXT NEXT ENT Press ENT to confirm TEST PGM Mode av Note the TEST LED on the DL205 MODE CHANGE Handheld indicates the CPU is in CPU T PGM TEST Mode 9 20 DL205 User Manual 4th Edition Rev B Chapter 9 Maintenance and Troubleshooting Test Displays With the Handheld Programmer you also have a more detailed display when you use TEST Mode For some instructions the TEST RUN mode display is more detailed than the status displays shown in RUN mode The following diagram shows an example of a Timer instruction display during TEST RUN mode RUN Mode TEST RUN Mode S B 1425 TMR TO K1000 TMR TO K1000 TO Contact S is off TO Contact S is off E is on Input to Timer Current Value E is on Holding Output States The ability to hold output states is very useful because it allows you to maintain key system I O points In some cases you may need to modify the program but you do not want certain operations to stop In normal Run Mode the outputs are turned off when you return to Program Mode In TEST RUN mode you can set e
7. Use AUX 5C to view the tables AUX 5C HISTORY D ERROR MESAGE gt ent AUX 5C HISTORY D ERROR MESAGE Example of an error display cir F sHFT C AUX ENT E252NEW I O CFG 08 09 21 10 11 15 Year Month Day Time DL205 User Manual 4th Edition Rev B l 9 7 Chapter 9 Maintenance and Troubleshooting System Error Codes The System error log contains 32 of the most recent errors that have been detected The errors that are trapped in the error log are a subset of all the error messages which the DL205 systems generate 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 230 V 240 M 250 1 V 260 Error Code 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 Description Error Code Description Software time out Invalid operation Invalid instruction RAM parity error in the CPU Bad operation CPU in Run CPU battery low Bad operation CPU in Test Run Memory cartridge battery low Bad operation CPU in Test Program Program memory exceeded Bad operation CPU in Program CPU memory cartridge missing Mode Switch not in TERM Wr
8. CR2354 1 Press the retaining clip on the battery door down and swing the battery door open DL250 1 DL260 2 Remove old battery and insert the new battery into the coin type slot with the larger side outwards 3 Close the battery door making sure that it locks securely in place 4 Make a note of the date the battery was installed WARNING Do not attempt to recharge the battery or dispose of an old battery by fire The battery may explode or release hazardous materials Diagnostics Diagnostics Your DL205 system performs many pre defined diagnostic routines with every CPU scan The diagnostics have been designed to detect various types of failures for the CPU and I O modules There are two primary error classes fatal and non fatal Fatal Errors 9 Fatal errors are errors the CPU has detected that offer a risk of the system not functioning safely or properly If the CPU is in Run Mode when the fatal error occurs the CPU will switch to Program 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 enter Run Mode until the error has been corrected Here are some examples of fatal errors e Base power supply failure e Parity error or CPU malfunction e I O configuration errors e Certain programming errors Non fatal Errors Non fatal errors are errors that are flagged by the CPU as requiring attention They can
9. status indicator Following the table will be a detailed analysis of each of these indicator problems Indicator Status Potential Problems 1 System voltage incorrect 2 Power supply CPU is faulty 3 Other component such an 1 0 module has power supply shorted 4 Power budget exceeded for the base being used 1 CPU programming error RUN will not come on 2 Switch in TERM position 3 Switch in STOP position DL250 1 DL260 only RUN flashing Firmware upgrade mode CPU on 1 Electrical noise interference 2 CPU defective BATT on 1 CPU battery low 2 CPU battery missing or disconnected Status Indicators IT 4 Nid 9 PWR O A Ru S GPU Batt E E cpu Mode Switch Port 1 DL240 few DL230 CPU CPU O CH on Analog ons Adjustments H ic nal PORTI iaiia Port 2 EE N E B porta j gpr N Status Indicators N cpu 3g o Cal 0 000 2900202020 o0000 i PoRT2 o 9 10 DL205 User Manual 4th Edition Rev B Mode Switch 4 we p pot2 Battery Slot ws
10. DL205 User Manual 4th Edition Rev B 9 29 Chapter 9 Maintenance and Troubleshooting E Notes 9 30 DL205 User Manual 4th Edition Rev B
11. an END statement prior to the portion that should be disabled When the CPU encounters the END statement it assumes it is the end of the program The following diagram shows an example Normal Program New END disables X10 and Y1 XO X2 O XO X2 YO D gt C X1 X3 X4 x1 X3 X4 1 X10 vA CD ED es X10 Y1 eno g PAUSE Instruction This instruction provides a quick way to allow the inputs or other logic to operate while disabling selected outputs The output image register is still updated but the output status is not written to the modules 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 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 Yo Yi a Pause X1 X3 X4 xo x2 YO 1 4 C X10 Y1 x1 X3 X4 C gt 1 4 X10 Y1 ED C GD 9 22 DL205 User Manual 4th Edition Rev B Normal Program XO x2 x1 x3 X4 V X10 In the example shown above you could trigger X20 which would execute the STOP instruction The CPU would enter Program Mode and all outputs would be turned off Chapter 9 Maintenance and Troubleshooting era ST
12. 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 The following example shows how to perform the duplicate reference check with a Handheld Programmer Use AUX 21 to perform syntax check aalle gt e i AUX 21 CHECK PRO 2 1 1 SYN 2 DUP REF 00024 E471 Select duplicate reference check You may not get the busy BUSY display if the program is not very long gt EN One of two displays will appear Error Display example DUP COIL REF 9 shows location in question Syntax OK display _ No pup REFS If you get an error 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 NOTE You can use the same coil in more than one location especially in programs using the Stage I instructions and or the OROUT instructions The Duplicate Reference check will find these outputs even though they may be used in an acceptable fashion DL205 User Manual 4th Edition Rev B 9 19 Chapter 9 Maintenance and Troubleshooting E TEST PGM and TEST RUN Modes Test Mode allows the CPU to start in TEST PGM mode enter TEST RUN mode run a fixed number of scans and return to TEST PGM mode You can sele
13. some important operations sequence 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 9 Mnemonic Description Mnemonic Not all instructions can be edited during a Run Time Edit session The following list shows Description Timer Or greater than or equal Or less than Fast timer Load data constant Accumulating timer Accumulating fast timer Load data double constant Counter Add data double constant Up Down counter Subtract data double constant 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 Store less than Shift accumulator right And greater than or equal And less than
14. to do an T O check independent of the application program for either the DL230 DL240 DL250 1 or DL260 follow the procedure below Action Use a handheld programmer or DirecfSOFT 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 equipment damage Make sure you have taken WARNING Depending on your application forcing 1 0 points may cause unpredictable machine all appropriate safety precautions prior to testing any 1 0 points Handheld Programmer Keystrokes Used to Test an Output Point ED XO X2 X9 T Be Insert an END statement f N S at the beginning of the x1 X3 X4 program This disables the remainder of the program ED 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 Y 10 Y 0 es ENT NEXT o
15. MAINTENANCE AND TROUBLESHOOTING In This Chapter Hardware Maintenance 0 cc eee eee eens 9 2 DIAQNOSUGS secu at er pei e cere ower dbhent steed 9 3 CPU Error INGICAIOIS 2s 26 bre gedaan ce do ioo CaS ete eee ee be 9 10 PWR Indicator 6 s5s ce 20d dees henna e ee eeu ieee eae me ees 9 11 Communications Problems si cs s i484 86440 be ReR ee tO RRR Ee 9 13 I O Module Troubleshooting 1534454 40 as0neeenwand deed ean 9 14 Noise Troubleshooting 22 iceeeienecesaeesacdeeenee tees 9 17 Machine Startup and Program Troubleshooting 9 18 Chapter 9 Maintenance and Troubleshooting Hardware Maintenance Standard Maintenance The DL205 is a low maintenance system requiring only a few periodic checks to help reduce the risks of problems Routine maintenance checks should be made regarding two key items e Air quality cabinet temperature airflow etc e CPU battery Air Quality Maintenance The quality of the air your system is exposed to can affect system performance If you have placed your system in an enclosure check to see that the ambient temperature is not exceeding the operating specifications If there are filters in the enclosure clean or replace them as necessary to ensure adequate airflow A good rule of thumb is to check your system environment every one to two months Make sure the DL205 is operating within the system operating specifications Low Battery Indicator The CPU has a batt
16. OP Instruction Sometimes during machine startup you need a way to quickly turn off all the outputs and return to Program Mode In addition to using the Test Modes and AUX 58 to configure each individual point you can also 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 Yo Y1 END STOP puts CPU in Program Mode X20 ED XO X2 yO X1 X3 X4 1 1 X10 Y1 ra XR CD DL205 User Manual 4th Edition Rev B 9 23 Chapter 9 Maintenance and Troubleshooting Run Time Edits The DL205 CPUs allow you 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 changes to the program Changes during Run Mode become effective immediately Make sure you f WARNING Only authorized personnel fully familiar with all aspects of the application should make thoroughly consider the impact of any changes to minimize the risk of personal injury or damage to equipment There are
17. Programmer and DirectSOFT provide error checking during program entry you may want to check a modified program 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 This check will find a wide variety of programming errors The following example shows how to use the syntax check with a Handheld Programmer 9 Use AUX 21 to perform syntax check ar fe E ul e AUX 21 CHECK PRO 1 SYN 2 DUP REF Select syntax check default selection You may not get the busy display BUSY if the program is not very long One of two displays will appear Error Display example m z 00050 E401 MISSING END shows location in question Syntax OK display NiO SYNTAX ERROR See the Error Codes Section for a complete listing of programming error codes If you get an error 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 9 18 DL205 User Manual 4th Edition Rev B Chapter 9 Maintenance and Troubleshooting nI Duplicate Reference 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
18. a type it is important to understand how the DL205 CPUs process the forcing requests WARNING Only authorized personnel fully familiar with all aspects of the application should make changes to the program Make sure you thoroughly consider the impact of any changes to minimize the risk of personal injury or damage to equipment There are two types of forcing available with the DL205 CPUs Chapter 3 provides a detailed description of how the CPU processes each type of forcing request e Regular Forcing This type of forcing can temporarily change the status of a discrete bit For example you may want to force an input on even though it is really off This allows you to change the point status that was stored in the image register This value will be valid until the image register location is written to during the next scan This is primarily useful during testing situations when you need to force a bit on to trigger another event e Bit Override DL240 DL250 1 or DL260 Bit override can be enabled on a point by point basis by using AUX 59 from the Handheld Programmer or by a menu option in DirectSOFT You can use Bit Override with X Y C T CT and S data types Bit override basically disables any changes to the discrete point by the CPU For example if you enable bit override for X1 and X1 is off at the time the CPU will not change the state of X1 This means that even if X1 comes on the CPU will not acknowledge the change Therefo
19. able 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 is no more than a large antenna waiting to introduce noise into the system therefore you should 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 e Electrical noise can enter the system through the power source for the CPU and I O Installing an isolation transformer for all AC sources can correct this problem DC power sources should be well grounded good quality power supplies Switching DC power supplies commonly generate more noise than linear supplies e Separate input wiring from output wiring Never run I O wiring close to high voltage wiring DL205 User Manual 4th Edition Rev B O 17 Chapter 9 Maintenance and Troubleshooting E Machine Startup and Program Troubleshooting The DL205 CPUs provide several features to help you debug your program before and during machine startup This section discusses the following topics which can be very helpful e Program Syntax Check e Duplicate Reference Check e Test Modes e Special Instructions Run Time Edits e Forcing I O Points Syntax Check Even though the Handheld
20. ach individual output to either turn off or to hold its last output state on the transition to TEST PGM mode You can use AUX 58 on the Handheld Programmer to select the action for each individual output This feature is also available via a menu option within DirectSOFT The following diagram shows the differences between RUN and TEST RUN modes RUN Mode to PGM Mode X0 X2 my x1 X3 X4 Outputs are OFF Z Cadi x10 Yt Status on final scan X0 X2 YO D x1 X3 X4 1 4 X10 Y1 D TEST RUN to TEST PGM XO X2 YO END T X1 X3 X4 Hold YO ON X10 Y1 C Let Y1 turn Ore END Before you decide that Test Mode is the perfect choice remember that the DL205 CPUs also allow you to edit the program during Run Mode The primary difference between the Test Modes and the Run Time Edit feature is you do not have to configure each individual I O point to hold the output status When you use Run Time Edits the CPU automatically maintains all outputs in their current states while the program is being updated DL205 User Manual 4th Edition Rev B 9 2 1 Chapter 9 Maintenance and Troubleshooting Special Instructions There are several instructions that can be used to help you debug your program during machine startup operations e END e PAUSE e STOP END Instruction If you need a way to quickly disable part of the program insert
21. ct from 1 to 65 525 scans Test Mode also allows you to maintain output status while you switch between Test Program and Test Run Modes You can select Test Modes from either the Handheld Programmer by using the MODE key or from DirectSOFT via a PLC Modes menu option The primary benefit of using the TEST mode is to maintain certain outputs and other parameters when the CPU transitions back to Test program mode For example you can use AUX 58 from the DL205 Handheld Programmer to configure the individual outputs CRs etc to hold their output state Also the CPU will maintain timer and counter current values when it switches to TEST PGM mode Handheld Programmer However you can use the Handheld to switch between Test Program and Test Run Ee NOTE You can only use DirectSOFT to specify the number of scans This feature is not supported on the Modes With the Handheld the actual mode entered when you first select Test Mode depends on the mode of operation at the time you make the request If the CPU is in Run Mode then TEST RUN is available If the mode is Program then TEST PGM is available Once you ve selected TEST Mode you can easily switch between TEST RUN and TEST PGM DirectSOFT provides more flexibility in selecting the various modes with different menu options The 9 following example shows how you can use the Handheld to select the Test Modes Use the MODE key to select TEST Modes example assumes Run Mode MODE CHANGE
22. dule if the indicator LED is on the input circuitry should be operating properly To verify proper functionality check to see that the LED goes off when the input signal is removed Leakage current can be a problem when connecting field devices to I O modules 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 rarallel with the input or output of the circuit The value of this resistor will depend on the amount of leakage current and the voltage applied but usually a 10KQ to 20KQ resistor will work Ensure the wattage rating of the resistor is correct for your application The easiest method to determine if a module has failed is to replace it if you have a spare However if you suspect another device to have caused the failure in the module that device may cause the same failure in the replacement module as well As a point of caution you may want to check devices or power supplies connected to the failed module before replacing it with a spare module DL205 User Manual 4th Edition Rev B 9 1 5 9 Chapter 9 Maintenance and Troubleshooting Testing Output Points Output points can be set on or off in the DL205 series CPUs In the DL240 and DL250 1 you can use AUX 59 Bit Override to force a point even while the program is running However this is not a recommended method to test the output points If you want
23. ery LED that indicates the battery voltage is low You should check this indicator periodically to determine if the battery needs replacing You can also detect low battery voltage from within the CPU program SP43 is a special relay that comes on when the battery needs to be replaced If you are using a DL240 CPU you can also use a programming device or operator interface to determine the battery voltage V7746 contains the battery voltage For example a value of 32 in V7746 would indicate a battery voltage of 3 2V CPU Battery Replacement The CPU battery is used to retain program V memory and the system parameters The life expectancy of this battery is five years NOTE Before installing or replacing your CPU battery back up your V memory and system parameters You can do this by using DirectSOFT to save the program V memory and system parameters to hard floppy disk on a personal computer To install the D2 BAT CPU battery in DL230 or SY DL240 CPUs 1 Gently push the battery connector onto the circuit DL230 board connector and i sa i 5 DL240 2 Push the battery into the retaining clip Don t use excessive force You may break the retaining clip 3 Make a note of the date the battery was installed 9 2 DL205 User Manual 4th Edition Rev B Chapter 9 Maintenance and Troubleshooting To install the D2 BAT 1 CPU battery in the DL250 1 and DL260 CPUs
24. for an output point Notice the bit override maintains the output in the current state If the output is on when the bit override is enabled then the output stays on If it is off then the output stays off Program Rung Override holds XO YO previous state and disables ou image register update by CPU YO override enabled XO at input mdoule YO in image register YO at output module The following diagram shows how you can use a programming device in combination with the bit override to change the status of the point Remember bit override only disables CPU changes You can still use a programming device to force the status of the point Plus since bit override maintains the current status this enables true forcing The example shown is for an output point but you can also use the other bit data types Prog ram Rung The force operation from the XO YO programming device can still ou change the point status YO override enabled XO at input mdoule YO force from programmer YO in image register YO at output module DL205 User Manual 4th Edition Rev B 9 27 Chapter 9 Maintenance and Troubleshooting The following diagrams show a brief example of how you could use the DL205 Handheld Programmer to fo
25. he failure indicators el i z g oc mi ofofofo o an on on oo on mm mm Program Control Information V7752 V7753 V7754 V7755 SP47 0020 0021 0002 0252 Ab Desired module ID code Current module ID code Location of conflict Fatal error code I O Configuration Error 9 14 DL205 User Manual 4th Edition Rev B E252 NEW I O CFG Chapter 9 Maintenance and Troubleshooting Some Quick Steps When troubleshooting the DL205 series I O modules there are a few facts you should be aware of which may assist you in quickly correcting an I O problem e The output modules cannot detect shorted or open output points If you suspect one or more points on an output module to be faulty you should measure the voltage drop from the common to the suspect point Remember when using a 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 to the point The I O point status indicators on the modules are logic side indicators This means the LED which indicates the on or off status reflects the status of the point in respect to the CPU On an output module the status indicators could be operating normally while the actual output device transistor triac etc could be damaged With an input mo
26. ite fail Unit is offline Invalid command Unit is online RAM failure CPU mode Terminal block missing CPU locked Missing 1 0 module Wrong password Blown fuse Password reset User 24V power supply failure Memory full Power fault Instruction missing Communication failure in the 1 0 chain Reference missing 1 0 parity error Bad 1 0 type New 1 0 configuration Bad Communications ID 1 0 out of range Out of memory Communications error 2 EEPROM Memory not blank Communications error 3 No Handheld Programmer EEPROM Communications error 6 memory only Time out Program only Communications error Bad write operation Invalid Text entry for Print Instruction Memory type error should be EEPROM Bad entry Mis compare Bad address Handheld Programmer system error Bad command Handheld Programmer ROM error Bad reference value 9 8 DL205 User Manual 4th Edition Rev B Invalid instruction Handheld Programmer RAM error Chapter 9 Maintenance and Troubleshooting Program Error Codes The following list shows the errors that can occur when there are problems with the program These errors will be detected when you try to place the CPU into Run Mode 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 mo
27. lication program with the FAULT instructions The V 240 CPU logs the error code the date and the time the error occurred There are two separate V 250 1 tables that store this information V 260 e Error Code Table the system logs up to 32 errors in the table When an error occurs the errors already in the table are pushed down and the most recent error is loaded into the top position If the table is full when an error occurs the oldest error is pushed erased from the table e Message Table the system logs up to 16 messages in this table When a message is triggered the messages already stored in the table are pushed down and the most recent message is loaded into the top position If the table is full when an error occurs the oldest message is pushed erased from the table The following diagram shows an example of an error table for messages Message 08 41 51 11 Conveyor 2 stopped 17 01 11 56 Conveyor 1 stopped 17 01 11 12 Limit SW1 failed 03 25 14 31 Saw Jam Detect You can access the error code table and the message table through DirectSOFT s PLC Diagnostic sub menus or from the Handheld Programmer Details on how to access these logs are provided in the DirectSOFT manual The following examples show you how to use the Handheld and AUX Function 5C to show the error codes The most recent error or message is always displayed You can use the PREV and NXT keys to scroll through the messages
28. n 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 BATT Indicator If the BATT indicator is on the CPU battery is either disconnected or needs replacing The battery voltage is continuously monitored while the system voltage is being supplied Communications Problems If you cannot establish communications with the CPU check these items e The cable is disconnected e The cable has a broken wire or has been wired incorrectly e The cable is improperly terminated or grounded e The device connected is not operating at the correct baud rate 9600 baud for the top port Use AUX 56 to select the baud rate for the bottom po
29. neither cause the CPU to change from Run Mode to Program Mode nor do they prevent the CPU from entering Run Mode There are special relays the application program can use to detect if a non fatal error has occurred The application program can then be used to take the system to an orderly shutdown or to switch the CPU to Program Mode if necessary Some examples of non fatal errors are e Backup battery voltage low e All I O module errors e Certain programming errors DL205 User Manual 4th Edition Rev B l 9 3 Chapter 9 Maintenance and Troubleshooting Finding Diagnostic Information Diagnostic information can be found in several places with varying levels of message detail e The CPU automatically logs error codes and any FAULT messages into two separate tables which can be viewed with the Handheld or DirectSOFT e The handheld programmer displays error numbers and short descriptions of the error e DirectSOFT provides the error number and an error message e Appendix B in this manual has a complete list of error messages sorted by error number Many of these messages point to supplemental memory locations which can be referenced for additional related information These memory references are in the form of V memory and SPs special relays The following two tables name the specific memory locations that correspond to certain types of error messages The special relay table also includes status indicators which can be used in p
30. ond clock Half carry occurred On alternate scans Carry occurred CPU Status Relays Result is negative sign Forced Run mode DL240 250 1 260 Pointer reference error Terminal Run mode Overflow Test Run mode DL240 250 1 260 Data is not in BCD Load zero Test program mode DL240 250 1 260 Communica tion Monitoring Relays Terminal Program mode SP116 DL230 DL240 CPU is communicating with another device STOP instruction was executed Interrupt enabled SP116 DL250 1 DL260 Port 2 is communicating with another device System Monitoring Relays Critical error Communication error on Port 2 DL250 1 DL260 only Non critical error Module busy Slot 0 Battery low Communication error Slot 0 Program memory error Module busy Slot 1 1 0 error Communication error Slot 1 Communications error Module busy Slot 2 1 0 configuration error Communication error Slot 2 Fault instruction was executed Module busy Slot 3 Watchdog timeout Communication error Slot 3 Syntax error Module busy Slot 4 Cannot solve the logic Communication error Slot 4 Intelligent module communication error Module busy Slot 5 Communication error Slot 5 Module busy Slot 6 Communication error Slot 6 Module busy Slot 7
31. rce an I O point Remember if you are using the Bit Override feature the CPU will retain the forced value until you disable the Bit Override or until you remove the force The image register will not be updated with the status from the input module Also the solution from the application program will not be XO YO co used to update the output image register The example assumes you have already placed the CPU into Run Mode From a clear display use the following keystrokes STAT ENT 16P STATUS BIT REF X Use the PREV or NEXT keys to select the Y data type Once the Y appears press 0 to start at YO 9 n i l E Use arrow keys to select point then use ON and OFF to change the status ON lt lt SHFT NS Regular Forcing with Direct Access From a clear display use the following keystrokes to force Y10 ON Y B A ON SHFT MLS 1 o SHET INS From a clear display use the following keystrokes to force Y10 OFF Y B A OFF SHFT MLS 1 o SHFT DEL 9 28 DL205 User Manual 4th Edition Rev B Solid fill indicates point is on BIT FORCE Y10 No fill indicates point is off
32. re if you used X1 in the program it would always be evaluated as off in this case If X1 was on when the bit override was enabled then X1 would always be evaluated as on There is an advantage available when you use the bit override feature The regular forcing is not disabled because the bit override is enabled For example if you enabled the Bit Override for YO and it was off at the time the CPU would not change the state of YO However you can still use a programming device to change the status If you use the programming device to force YO on it will remain on and the CPU will not change the state of YO If you then force YO off the CPU will maintain YO as off The CPU will never update the point with the results from the application program or from the I O update until the bit override is removed from the point 9 26 DL205 User Manual 4th Edition Rev B Chapter 9 Maintenance and Troubleshooting The following diagrams show how the bit override works for both input and output points The example uses a simple rung but the concepts are similar for any type of bit memory Program Rung Override holds XO YO previous state and disables ut image register update by CPU X0 override enabled XO at input module XO in image register YO in image register The following diagram shows how the bit override works
33. re complete description of the error codes Error Code Description Error Code Description No Program in CPU Stack Overflow Missing END statement Stack Underflow Missing LBL Logic Error Missing RET Missing Circuit Missing FOR Duplicate coil reference Missing NEXT Duplicate TMR reference Missing IRT Duplicate CNT reference SBR LBL gt 64 CV position error FOR NEXT gt 64 CV not connected Duplicate stage reference CV exceeded Duplicate SBR LBL reference CVJMP placement error Nested loops No CV Invalid ISG SG address No CVJMP Invalid jump GOTO address BCALL placement error Invalid SBR address No Block defined Invalid RTC address Block position error Invalid RT address Block CR identifier error Invalid INT address No Block stage Invalid IRTC address ISG position error Invalid IRT address BEND position error Invalid Data address BEND error ACON NCON Bad MLS MLR X input used as output coil Missing T C Bad TMRA Bad CNT Bad SR DL205 User Manual 4th Edition Rev B 9 9 No BEND Chapter 9 Maintenance and Troubleshooting CPU Error Indicators The DL205 CPUs have indicators on the front to help you diagnose problems with the system The table below gives a quick reference of potential problems associated with each
34. rogramming For a more detailed description of each of these special relays refer to Appendix D V memory Locations Corresponding to Error Codes Diagnostic Error Class Error Category V memory Battery Voltage DL240 only Shows battery voltage to tenths 32 is 3 2V V7746 User Defined Error code used with FAULT instruction V7751 Correct module ID code V7752 1 0 Configuration Incorrect module ID code V7753 Base and Slot number where error occurs V7754 Fatal Error code V7755 System Error Major Error code V7756 Minor Error code V7757 Base and slot number where error occurs V7760 Module Diagnostic Always holds a 0 V7761 Error code V7762 Address where syntax error occurs V7763 Error code found during syntax check V7764 Number of scans since last Program to Run Mode transition V7765 Current scan time ms V7775 Minimum scan time ms V7776 Maximum scan time ms V7777 Grammatical CPU Scan 9 4 DL205 User Manual 4th Edition Rev B Chapter 9 Maintenance and Troubleshooting Special Relays SP Corresponding to Error Codes Startup and Real time Relays Accumulator Status Relays On first scan only Acc is less than value Always ON Acc is equal to value Always OFF Acc is greater than value 1 minute clock Acc result is zero 1 second clock Half borrow occurred 100 millisecond clock Borrow occurred 50 millisec
35. rt on a DL240 DL250 1 and DL260 e The device connected to the port is sending data incorrectly e A grounding difference exists between the two devices e Electrical noise is causing intermittent errors e The CPU has a bad communication port and the CPU should be replaced If an error occurs the indicator will come on and stay on until a successful communication has been completed DL205 User Manual 4th Edition Rev B 9 13 Chapter 9 Maintenance and Troubleshooting 1 0 Module Troubleshooting Things to Check If you suspect an I O error there are several things that could be causing the problem e A blown fuse e A loose terminal block e The 24 VDC supply has failed e The module has failed e The I O configuration check detects a change in the I O configuration T O Diagnostics If the modules are not providing any clues to the problem run AUX 42 from the handheld programmer or I O diagnostics in DirectSOFT Both options will provide the base number the slot number and the problem with the module Once the problem is corrected the indicators will reset An I O error will not cause the CPU to switch from the run to program mode however there are special relays SPs available in the CPU which will allow this error to be read in ladder logic The application program can then take the required action such as entering the program mode or initiating an orderly shutdown The following figure shows an example of t
36. surges it is possible the CPU and power supply have been damaged If you suspect this is the cause of the power supply damage a line conditioner which removes damaging voltage spikes should be used in the future DL205 User Manual 4th Edition Rev B 9 11 Chapter 9 Maintenance and Troubleshooting Device or Module causing the Power Supply to Shutdown It is possible a faulty module or external device using the system 5V can shut down the power supply This 5V can be coming from the base or from the CPU communication ports To test for a device causing this problem 1 Turn off power to the CPU 2 Disconnect all external devices i e communication cables from the CPU 3 Reapply power to the system If the power supply operates normally you may have either a shorted device or a shorted cable If the power supply does not operate normally then test for a module causing the problem by following the steps below If the PWR LED operates normally the problem could be in one of the modules To isolate which module is causing the problem disconnect the system power and remove one module at a time until the PWR LED operates normally Follow the procedure below e Turn off power to the base e Remove a module from the base e Reapply power to the base Bent base connector pins on the module can cause this problem Check to see the connector is not the problem Power Budget Exceeded AN If the machine had been operating correc
37. tly for a considerable amount of time prior to the indicator going off the power budget is not likely to be the problem Power budgeting problems usually occur during system start up when the PLC is under operation and the inputs outputs are requiring more current than the base power supply can provide WARNING The PLC may reset if the power budget is exceeded If there is any doubt about the system power budget please check it at this time Exceeding the power budget can cause unpredictable results which can cause damage and injury Verify the modules in the base operate within the power budget for the chosen base You can find these tables in Chapter 4 Bases and 1 0 Configuration 9 12 DL205 User Manual 4th Edition Rev B Chapter 9 Maintenance and Troubleshooting 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 If the RUN light is flashing the PLC is in firmware upgrade mode If you are using a DL240 DL250 1 or DL260 and you are trying to change the modes with a programming device make sure the mode switch is in the TERM position Both of the programming devices Handheld Programmer and DirectSOFT will return an error message describing the problem Depending on the error there may also be a
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