Chapter. Maintenance and. Troubleshooting. In This Chapter...

Transcription

1 hapter Maintenance and Troubleshooting In This hapter... Hardware System Maintenance... iagnostics... PU Indicators... ommunications Problems... I/O Point Troubleshooting... Noise Troubleshooting... 0 Machine Startup and Program Troubleshooting...

2 hapter : Maintenance and Troubleshooting 0 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 PL and control system is good practice, and should include the following items: iagnostics ir Temperature Monitor the air temperature in the control cabinet, so the operating temperature range of any component is not exceeded. ir 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. leaning the Unit heck 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. o not let water enter the case through the air vents and do not use strong detergents because this may discolor the case. iagnostics Your L0 Micro PL performs many pre-defined diagnostic routines with every PU scan. The diagnostics can detect various errors or failures in the PL. 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 PU 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 PU is in Program Mode, the PU 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 PU 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 PU. 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 PU to Program Mode if desired. n example of a non-fatal error is: Particular programming errors - The programming devices will notify you of an error if one occurs while online. irectsoft provides the error number and an error message. The handheld programmer displays error numbers and short descriptions of the error. ppendix has a complete list of error messages in order by error number. Many error messages point to supplemental V-memory locations which contain related information. Special relays (SP contacts) also provide error indications (refer to ppendix ). L0 Micro PL User Manual, rd Edition, Rev. E

3 hapter : Maintenance and Troubleshooting V-memory Error ode Locations The following table names the specific memory locations that correspond to certain types of error messages. Error lass Error ategory iagnostic V-memory User-efined Error code used with FULT instruction V Fatal Error code V System Error Major Error code V Minor Error code V Grammatical ddress where syntax error occurs V Error ode found during syntax check V Number of scans since last Program to Run Mode transition V PU Scan urrent scan time (ms) V Minimum scan time (ms) V Maximum scan time (ms) V Special Relays (SP) orresponding to Error odes 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 ppendix. PU Status Relays SP Forced Run mode SP Terminal Run mode SP Test Run mode SP Test stop mode SP Terminal Program mode SP Forced stop SP0 STOP instruction was executed SP Interrupt enabled System Monitoring Relays SP Override setup SP Scan control error SP0 ritical error SP Non-critical error SP iagnostics error SP Program memory error SP I/O error SP ommunications error SP0 Fault instruction was executed SP Watchdog timeout SP Syntax error SP annot solve the logic SP ommunication error SP Table instruction overrun ccumulator Status Relays SP0 cc. is less than value SP cc. is equal to value SP cc. is greater than value SP cc. result is zero SP Half borrow occurred SP orrow occurred SP Half carry occurred SP arry occurred SP0 Result is negative (sign) SP Pointer reference error SP Overflow SP ata is not in SP Load zero 0 L0 Micro PL User Manual, rd Edition, Rev. E -

4 hapter : Maintenance and Troubleshooting 0 L0 Micro PL Error odes These errors can be generated by the PU or by the Handheld Programmer, depending on the actual error. ppendix 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 ode escription E00 Software time-out E00 Invalid instruction(rm parity error in the PU) E0 Write failed E Invalid command E ommunications error E ommunications error E ommunications error E ommunications error E0 Time out E ommunications error E0 HP Peripheral port time-out E0 ad entry E0 ad address E0 ad command E0 ad reference / value E0 Invalid instruction E0 Invalid operation E0 ad operation PU in Run E ad operation PU in Test Run E ad operation PU in Test Program E ad operation PU in Program E Mode Switch not in Term position Error ode escription E Unit is offline E Unit is online E PU mode E0 PU locked E Wrong password E Password reset E0 Memory full E0 Instruction missing E0 Reference missing E0 Out of memory E EEPROM Memory not blank E No Handheld Programmer EEPROM E V memory only E Program only E ad write operation E Memory type error (should be EEPROM) E0 Mis-compare E0 Handheld Programmer system error E Handheld Programmer ROM error E Handheld Programmer RM error - L0 Micro PL User Manual, rd Edition, Rev. E

5 hapter : Maintenance and Troubleshooting Program Error odes The following table lists program syntax and runtime error codes. Error detection occurs during a Program-to-Run mode transition, or when you use UX heck Program. The PU will also turn on SP and store the error code in V. ppendix provides a more complete description of the error codes. Error ode escription E** No Program in PU E0 Missing EN statement E0 Missing LL E0 Missing RET E0 Missing FOR E0 Missing NEXT E0 Missing IRT E SR / LL > E uplicate Stage reference E uplicate SR/LL reference E Nested Loop E Invalid ISG/SG address E Invalid ISG / SG address E Invalid RT E Invalid RT E Invalid INT address E Invalid IRT Error ode escription E Invalid IRT address E0 Invalid ata ddress E ON/NON E ad MLS/MLR E Missing T/ E ad TMR E ad NT E ad SR E Stack Overflow E Stack Underflow E Logic Error E Missing ircuit E uplicate oil reference E uplicate TMR reference E uplicate NT reference E Print Instruction 0 L0 Micro PL User Manual, rd Edition, Rev. E -

6 hapter : Maintenance and Troubleshooting 0 PU Indicators The L0 Micro PLs 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 PWR (Green LE off) System voltage incorrect PL power supply faulty RUN (Green LE off) PU programming error PU in program mode RUN (Green LE flashing) PU in firmware upgrade mode PU (Red LE on) Electrical noise interference Internal PU defective PU (linking Red LE) Low backup battery (refer to page -) PWR Indicator In general there are three reasons for the PU power status LE (PWR) to be OFF:. Power to the unit is incorrect or is not applied.. PL power supply is faulty.. Other component(s) have the power supply shut down. If the voltage to the power supply is not correct, the PL may not operate properly or may not operate at all. Use the following guidelines to correct the problem. WRNING: To minimize the risk of electrical shock, always disconnect the system power before inspecting the physical wiring.. First, disconnect the external power.. Verify that all external circuit breakers or fuses are still intact.. heck 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 L0 power input 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, the PL internal supply may be faulty. The best way to check for a faulty PL is to substitute a known good one to see if this corrects the problem. The removable connectors on the L0 make this relatively easy. If there has been a major power surge, it is possible the PL internal power supply has been damaged. If you suspect this is the cause of the power supply damage, consider installing an line conditioner to attenuate damaging voltage spikes in the future. - L0 Micro PL User Manual, rd Edition, Rev. E

7 hapter : Maintenance and Troubleshooting RUN Indicator If the PU will not enter the Run mode (the RUN indicator is off), the problem is usually in the application program, unless the PU has a fatal error. If a fatal error has occurred, the PU LE should be on. (You can use a programming device to determine the cause of the error.) oth of the programming devices, Handheld Programmer and irectsoft, will return an error message describing the problem. epending on the error, there may also be an UX function you can use to help diagnose the problem. The most common programming error is Missing EN Statement. ll application programs require an EN statement for proper termination. complete list of error codes can be found in ppendix. The RUN indicator will flash (blink) whenever the PU is in the firmware upgrade mode. PU Indicator If the PU indicator is on, a fatal error has occurred in the PU. 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 PU from an outside source. heck 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 PU. If the PU indicator is blinking, the backup battery is low (refer to page -). ommunications Problems If you cannot establish communications with the PU, check these items. 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 (00 baud). The device connected to the port is sending data incorrectly, or another application is running on the device. grounding difference exists between the two devices. Electrical noise is causing intermittent errors. The PL has a bad communication port and should be replaced. For problems in communicating with irectsoft on a personal computer, refer to the irectsoft programming user manual. It includes a troubleshooting section that can help you diagnose P problems in communications port setup, address or interrupt conflicts, etc. 0 L0 Micro PL User Manual, rd Edition, Rev. E -

8 hapter : Maintenance and Troubleshooting 0 I/O Point Troubleshooting Possible auses If you suspect an I/O error, there are several things that could be causing the problem. High-Speed I/O configuration error blown fuse in your machine or panel (the L0 does not have internal I/O fuses) loose terminal block The auxiliary V supply has failed The Input or Output ircuit has failed Some Quick Steps When troubleshooting the L0 Micro PLs, please be aware of the following facts which may assist you in quickly correcting an I/O problem. HSIO configuration errors are commonly mistaken for I/O point failure during program development. If the I/O point in question is in X, or Y, check all parameter locations listed in hapter 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 igital Volt Meter, leakage current from an output device such as a triac or a transistor must be considered. 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 LE which indicates the on or off status reflects the status of the point with respect to the PU. 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 LE is on, the input circuitry is probably operating properly. Verify the LE 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 current and the voltage applied but usually a 0K to 0K resistor will work. Verify the wattage rating of the resistor is correct for your application. ecause of the removable terminal blocks on the L0, 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 PL as well. s 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. - L0 Micro PL User Manual, rd Edition, Rev. E

9 hapter : Maintenance and Troubleshooting Output points can be set on or off in the L0 series PUs. If you want to do an I/O checkout independent of the application program, follow the procedure below: Step ction Use a handheld programmer or irectsoft to communicate online to the PL. hange to Program Mode. Go to address 0. WRNING: epending on your application, forcing I/O points may cause unpredictable machine operation that can result in a risk of personal injury or equipment damage. Make sure you have taken all appropriate safety precautions prior to testing any I/O points. Handheld Programmer Keystrokes Used to Test an Output Point X Insert an EN statement at address 0. (This will cause program execution to occur only at address 0 and prevent the application program from turning the I/O points on or off). hange to Run Mode. Use the programming device to set (turn) on or off the points you wish to test. When you finish testing I/O points delete the EN statement at address 0. From a clear display, use the following keystrokes ST T Use the PREV or NEXT keys to select the Y data type NEXT 0 X X X X X Use arrow keys to select point, then use ON and OFF to change the status SHFT ON INS EN Y EN P STTUS IT REF X Insert an EN statement at the beginning of the program. This disables the remainder of the program. Y 0 Y 0 Y is now on 0 L0 Micro PL User Manual, rd Edition, Rev. E -

10 hapter : Maintenance and Troubleshooting 0 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. onducted 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 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. 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. loose wire can act as a large antenna, introducing noise into the system, so, tighten all connections in your system. Loose ground wires are more susceptible to noise than the other wires in your system. Review hapter 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 PL and I/O circuits. Installing an isolation transformer for all sources can correct this problem. sources should be wellgrounded good quality supplies. Separate input wiring from output wiring. Never run low-voltage I/O wiring close to high voltage wiring. -0 L0 Micro PL User Manual, rd Edition, Rev. E

11 hapter : Maintenance and Troubleshooting Machine Startup and Program Troubleshooting The L0 Micro PLs 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 heck uplicate Reference heck Special Instructions Run Time Edits Forcing I/O Points Syntax heck Even though the Handheld Programmer and irect SOFT provide error checking during program entry, you may want to check a program that has been modified. oth programming devices offer a way to check the program syntax. For example, you can use UX, HEK PROGRM to check the program syntax from a Handheld Programmer, or you can use the PL iagnostics menu option within irect SOFT. 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 UX to perform syntax check LR Select syntax check (default selection) UX (You may not get the busy display if the program is not very long.) One of two displays will appear Error isplay (example) Syntax OK display UX HEK PRO :SYN :UP REF USY $0000 E0 MISSING EN (shows location in question) NO SYNTX ERROR? See the Error odes Section for a complete listing of programming error codes. If you get an error, just press LR and the Handheld will display the instruction where the error occurred. orrect the problem and continue running the Syntax check until the NO SYNTX ERROR message appears. 0 L0 Micro PL User Manual, rd Edition, Rev. E -

12 hapter : Maintenance and Troubleshooting 0 - Special Instructions There are several instructions that can be used to help you debug your program during machine startup operations. EN PUSE STOP EN Instruction: If you need a way to quickly disable part of the program, just insert an EN statement prior to the portion that should be disabled. When the PU encounters the EN statement, it assumes that is the end of the program. The following diagram shows an example. X PUSE 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 circuits are not. For example, you could make this conditional by adding an input contact or R 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. X Normal Program X X S T O P 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 PU 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 PU to Program Mode. L0 Micro PL User Manual, rd Edition, Rev. E X Normal Program X X X Y EN Y EN New EN disables and Y X X X X PUSE disables and Y X X X X EN Y EN Y PUSE Y EN

13 hapter : Maintenance and Troubleshooting Normal Program STOP puts PU in Program Mode X X X X X Y EN In the example shown above, you could trigger X which would execute the STOP instruction. The PU would enter Program Mode and all outputs would be turned off. uplicate Reference heck You can also check for multiple uses of the same output coil. oth programming devices offer a way to check for this condition.. For example, you can UX, HEK PROGRM to check for duplicate references from a Handheld Programmer, or you can use the PL iagnostics menu option within irectsoft. The following example shows how to perform the duplicate reference check with a Handheld Programmer. If you get an error, just press LR and the Handheld will display the instruction where the error occurred. orrect the problem and continue running the uplicate Reference check until no duplicate references are found. Use UX to perform syntax check LR Select duplicate reference check UX (You may not get the busy display if the program is not very long.) One of two displays will appear Error isplay (example) (shows location in question) Syntax OK display NOTE: You can use the same coil in more than one location, especially in programs containing Stage instructions and / or OROUT instructions. The uplicate Reference check will find occurrences, even though they are acceptable. X X X X X $000 E UP OIL REF NO UP REFS? X UX HEK PRO :SYN :UP REF USY ST OP Y EN 0 L0 Micro PL User Manual, rd Edition, Rev. E -

14 hapter : Maintenance and Troubleshooting 0 Run Time Edits The L0 Micro PL allows you to make changes to the application program during Run Mode. These edits are not bumpless. Instead, PU 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. WRNING: Only authorized personnel fully familiar with all aspects of the application should make changes to the program. hanges 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.. If there is a syntax error in the new instruction, the PU will not enter the Run Mode.. 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.. Input point changes are not acknowledged during Run Time Edits, so, if you re using a highspeed operation and a critical input comes on, the PU 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 TMR TMRF TMR TMRF NT U SGNT STR, STRN N, NN OR, ORN STRE, STRNE NE, NNE ORE, ORNE STR, STRN N, NN escription Timer Fast timer ccumulating timer ccumulating fast timer ounter Up / own counter Stage counter Store, Store not (oolean) nd, nd not (oolean) Or, Or not (oolean) Store equal, Store not equal nd equal, nd not equal Or equal, Or not equal Store greater than or equal Store less than (omparative oolean) nd greater than or equal nd less than (omparative oolean) Mnemonic OR, ORN L L SU MUL IV MP N OR XOR LF OUTF SHFR SHFL NON escription Or greater than or equal or less than (omparative oolean) Load data (constant) Load data double (constant) dd data double (constant) Subtract data double (constant) Multiply (constant) ivide (constant) ompare accumulator (constant) nd accumulator (constant) Or accumulator (constant) Exclusive or accumulator (constant) Load discrete points to accumulator Output accumulator to discrete points Shift accumulator right Shift accumulator left Numeric constant - L0 Micro PL User Manual, rd Edition, Rev. E

15 hapter : Maintenance and Troubleshooting Run Time Edit Example We ll use the program logic shown to describe how this process works. In the example, we ll change to 0. Note, the example assumes you have already placed the PU in Run Mode. Use the MOE key to select Run Time Edits MOE Press to confirm the Run Time Edits Find the instruction you want to change () SHFT NEXT X SET NEXT 0 Press the arrow key to move to the X. Then enter the new contact (0). Press to confirm the change. (Note, the RUN LE on the HPP Handheld starts flashing to indicate Run T ime Edits are enabled.) SHFT SHFT F REF FIN 0 (Note, once you press, the next address is displayed. X OUT 0 *MOE HNGE* RUN TIME EIT? *MOE HNGE* RUNTIME EITS $00000 STR RUNTIME EIT? STR 0 OR 0 0 L0 Micro PL User Manual, rd Edition, Rev. E -

16 hapter : Maintenance and Troubleshooting 0 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. efore you use a programming device to force any data type, it is important to understand how the L0 PUs process the forcing requests. WRNING: 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 L0 PUs. (hapter provides a detailed description of how the PU processes each type of forcing request). 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. it Override: it override can be enabled on a point-by-point basis by using UX from the Handheld Programmer or by a menu option in irectsoft. You can use it Override with X, Y,, T, T, and S data types. it override basically disables any changes to the discrete point by the PU. For example, if you enable bit override for X, and X is off at the time, the PU will not change the state of X. This means that even if X comes on, the PU will not acknowledge the change. Therefore, if you used X in the program, it would always be evaluated as off, in this case. If X was on when the bit override was enabled, then X would always be evaluated as on. There is an advantage available when you use the it Override feature. The Regular Forcing is not disabled because the it Override is enabled. For example, if you enabled the it Override for and it was off at the time, the PU would not change the state of. However, you can still use a programming device to change the status. If you use the programming device to force on, it will remain on and the PU will not change the state of. If you then force off, the PU will maintain as off. The PU will never update the point with the results from the application program or from the I/O update until the it Override is removed from the point. - L0 Micro PL User Manual, rd Edition, Rev. E

17 hapter : 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 OUT override enabled at input module in image register in image register Override holds previous state and disables image register update by PU The following diagram shows how the bit override works 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 OUT override enabled at input module in image register at output module Override holds previous state and disables image register update by PU 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 PU 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. Program Rung OUT override enabled at input module force from programmer in image register at output module The force operation from the programming device can still change the point status. 0 L0 Micro PL User Manual, rd Edition, Rev. E -

18 hapter : Maintenance and Troubleshooting 0 - The following diagrams show a brief example of how you could use the L0 Handheld Programmer to force an I/O point. Remember, if you are using the it Override feature, the PU will retain the forced value until you disable the it Override or until you remove the force. The image register will not be updated with the status from the input module. lso, the solution from the application program will not be used to update the output image register. The example assumes you have already placed the PU into Run Mode. From a clear display, use the following keystrokes STT NEXT Use the PREV or NEXT keys to select the Y data type. Once the Y appears, press 0 to start at. 0 Y MLS L0 Micro PL User Manual, rd Edition, Rev. E 0 P STTUS IT REF X OUT Y 0 Y 0 Use arrow keys to select point, then use ON and OFF to change the status SHFT Regular Forcing with irect ccess From a clear display, use the following keystrokes to force ON. Solid fill indicates point is on. SHFT SHFT Y MLS ON INS 0 0 SHFT SHFT ON INS OFF EL Y is now on Y 0 Y 0 Solid fill indicates point is on. IT FORE From a clear display, use the following keystrokes to force OFF. No fill indicates point is off. No fill indicates point is off. IT FORE

19 hapter : Maintenance and Troubleshooting it Override Forcing From a clear display, use the following keystrokes to turn on the override bit for. X SET 0 SHFT ON INS Solid fill indicates point is on. IT FORE SET Y 0 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. Solid fill indicates point is on. for. S RST 0 SHFT ON INS Solid fill indicates point is on. IT FORE RST Y 0 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. it Override Indicators Override bit indicators are also shown on the handheld programmer status display. elow are the keystrokes to call the status display for. From a clear display, use the following keystrokes to display the status of. STT NEXT 0 Y 0 Y 0 Point is on Override bit is on 0 L0 Micro PL User Manual, rd Edition, Rev. E -

20 hapter : Maintenance and Troubleshooting 0 Reset the PL to Factory efaults NOTE: Resetting to factory defaults will not clear any password stored in the PL. Resetting a irectlogic PL to Factory efaults is a two-step process. e sure to have a verified backup of your program using Save Project to isk from the File menu before performing this procedure. Please be aware that the program as well as any settings will be erased and not all settings are stored in the project. In particular you will need to write down any settings for Secondary ommunications Ports and manually set the ports up after resetting the PL to factory defaults. Step One While connected to the PL with irectsoft, go to the PL menu and select; lear PL Memory. heck the LL box at the bottom of the list and press OK. Step Two While connected with irectsoft, go the PL menu and then to the Setup submenu and select; Initialize Scratch Pad and press Ok. NOTE: ll configurable communications ports will be reset to factory default state. If you are connected via Port or another configurable port, you may be disconnected when this operation is complete. NOTE: Retentive ranges will be reset to the factory settings.. NOTE: Manually addressed IO will be reset to factory default settings.. -0 L0 Micro PL User Manual, rd Edition, Rev. E

21 hapter : Maintenance and Troubleshooting 0 The PL has now been reset to factory dafaults and you can proceed to program the PL. 0 L0 Micro PL User Manual, rd Edition, Rev. E -

22 hapter : Maintenance and Troubleshooting 0 Notes: - L0 Micro PL User Manual, rd Edition, Rev. E