Troubleshooting

This is the web edition of the original ‎⮫ AC500-S safety user manual, version 1.3.2. This web edition is provided for quick reference only. The original safety user manual must be used to meet functional safety application requirements.

Error messages in the diagnosis buffer of non-safety CPU include a description, which shall help you to fix potential problems with AC500-S configuration. If some of the problems persist or no error messages are available in the diagnosis buffer, contact ABB technical support for further details.

NOTICE

Make sure that safety I/O modules are properly attached to TU582-S terminal unit with a good electrical contact to avoid unintended system state with possibly wrong LED states.

⮫ “Mounting, dimensions and electrical connection”

Below you can find a list of known issues and solutions related to AC500-S safety PLC components:

ID	Behavior	Potential cause	Remedy
1.	Safety CPU is in RUN or DEBUG RUN state, but all safety I/O modules suddenly go to RUN (module passivation) state.	Your program may contain endless loop which prevents safety CPU to send valid safety telegrams to safety I/O modules in a proper time manner (within configured watchdog time).	Check (debug) your safety application program and make sure that no endless loop(s) are in your safety application program.
2.	No log in is possible to the safety CPU from the safety project.	Visualization was connected directly to the safety CPU, which blocks the connection to the safety CPU. Only one connection to the safety CPU is allowed at a time.	Disconnect visualization from the safety CPU.
3.	During closing or saving of the project, modification of the safety project, etc. with Automation Builder, you may see that no reaction comes from the Automation Builder and/or safety project. It is as if the application hangs.	The user management of Automation Builder requires that you confirm your log-on credentials for safety components and issues a log-on message box which is not in the foreground. Your previous log-on session has expired.	Find a log-on message in the background of your Windows desktop, log-on and continue your previous actions. Set longer user log-on session time for Automation Builder if this behavior repeats. ⮫ “Settings dialog”
4.	Your safety digital input channel is occasionally passivated with an internal error diagnostic message on non-safety CPU. With AC500 V2 non-safety CPU: error severity: E3, component: 14, device: 1 ... 10, module: 31, channel: 31, error: 43 With AC500 V3 non-safety CPU: error severity: 3, error code: 16171	One of potential reasons is that your input signal frequency exceeded an allowed input channel signal frequency⮫ allowed frequency ranges.	Check that your input signal does not exceed the allowed digital input signal frequency.
5.	DX581-S module is powered on, but no power supply is connected to UP clamps of DX581-S module.	Wiring error on DX581-S module when +24 V DC is connected to at least one of the safety digital output clamps of DX581-S. As a result, DX581-S is powered on through safety digital outputs.	Check the wiring of DX581-S and disconnect +24 V DC from the safety digital output clamp(s).
6.	Some channels of a safety I/O module or a complete safety I/O module is occasionally passivated without a reason (wiring is correct, etc.).	No proper electrical contact between a safety I/O module and TU582-S terminal unit.	Make sure that you pressed the safety I/O module into TU582-S terminal unit with a force of at least 100 N, as prescribed in AC500-S checklists.
7.	With the increased number of safety I/O modules in the system, it takes longer to execute “Create boot project” command for the safety CPU.	The safety CPU is a single-threaded system. The more safety I/O modules are in the system, the higher is the internal cycle time of the safety CPU to process safety I/O relevant data.	Currently, there is no possibility to change this behavior other than to split safety I/Os to different safety CPUs, so that each safety CPU has less safety I/Os to handle.
8.	After log in to safety CPU using AC500-S Programming Tool, one can observe a long list of internal constants with a green font color for PROFIsafe F-Host instances.	The option “Replace constants” is selected.	In AC500-S Programming Tool, go to menu “Project Options Build” and unselect option “Replace constants”.
9.	No valid safety project can be generated (PROFIsafe callback functions are missing and no safety I/O mapping is created).	A potential reason is that you selected in “Object Properties... Access rights” for any of the POUs in the safety project tree the following option: “No Access” or “Read Access” for all “User Groups” with “Apply to all” selection.	Start safety project, log in and go to “Object Properties... Access rights” for any of the POUs in the safety project tree to set “Full access” for any of user groups followed by selection of “Apply to all”. After this, you can successfully repeat “Create Safety Configuration Data” command for your safety project from Automation Builder.
10.	I call CurTimeEx FB from library Safety_SysLibTime.lib and always get "0" values on the outputs.	CurTimeEx FB is not implemented in the current version of the safety CPU and is reserved for future use.	Do not use CurTimeEx FB in your safety application program.
11.	Set "Enable debug" parameter to “OFF” on the safety CPU. Create boot projects for the safety CPU and the non-safety CPU. Execute a power cycle. Compare safety boot project CRCs on your PC and the safety CPU. The comparison shows that they are the same, which is OK. Try to create a boot project for the safety CPU. An error message follows because of "Enable debug" set to “OFF” for the safety CPU, which is OK. Repeat the comparison of boot project CRCs on your PC and the safety CPU. They are reported to be not equal now (boot project CRC for the safety CPU is shown as CDCDCDCD), which can be misleading since the boot project on the safety CPU was not changed.	AC500-S Programming Tool does not support the described use case.	After power cycle of safety CPU, the correct boot project CRC shall be shown for the safety CPU.
12.	The serial driver is used to connect to safety CPU. In AC500-S Programming Tool, one executes “Login” command shortly followed by “Logout” command and shortly after this the “Login” command is again executed. After second log in attempt, the communication error is shown in AC500-S Programming Tool.	The serial driver does not have enough time to be re-initialized.	Wait for at least 20 seconds before executing “Login” command after “Logout” was performed.
13.	In AC500-S Programming Tool, one executes “Login” command and uses “setpwd” PLC browser command to set a new password, e.g., "PWD1" for the safety CPU. Power cycle is executed for the safety CPU, but AC500-S Programming Tool remains open on end-user PC. One executes “Login” command and enters the new password "PWD1", which was set in Step 1. One uses “setpwd” PLC browser command to set a new password, e.g., PWD2, for the safety CPU. Power cycle is executed for the safety CPU, but AC500-S Programming Tool remains open on end-user PC. One executes “Login” command and an error message is shown "You have entered a wrong PLC password!". After pressing “OK”, you still have a possibility to enter a new password "PWD2" and successfully log in to safety CPU.	AC500-S Programming Tool attempts to log in to the safety CPU with an old password.	After resetting the safety CPU password, close AC500-S Programming Tool and open it again. The error message will not appear again.
14.	After power-on, safety I/O module goes to SAFE STOP state with both ERR LEDs = ON.	The configured F_Dest_Add value in Automation Builder project is not equal to the PROFIsafe address switch value on the safety I/O module.	Make sure that F_Dest_Add value in Automation Builder project is equal to the PROFIsafe address switch value on the safety I/O module.
15.	No log in to the safety CPU is possible.	Wrong “Communication parameters” settings are used.	In AC500-S Programming Tool, check that correct settings of “Communication parameters” are used to connect to the safety CPU.
16.	After the boot project is loaded to the safety CPU, sometimes the V2 non-safety CPU seems to do nothing for about 45 seconds until its ERR-LED is switched on.	Timeout in V2 non-safety CPU.	Such situation can be observed very seldom. There is no remedy for this behavior of V2 non-safety CPU at the moment.
17.	After power-on of the safety CPU, it may happen that the safety CPU does not go to RUN mode. DIAG LED is ON and no boot project is loaded to the safety CPU. If you attempt to log in to the safety CPU, then the following error message can be seen in AC500-S Programming Tool: "No program on the controller! Download the new program?".	Safety CPU power dip function is triggered if the pause between the power-off and the following power-on phase is less than 1.5 s. The boot project is still on the safety CPU, but not loaded due to power dip detection. Thus, there is no need to reload any boot project to the safety CPU.	Do power-off and power-on of the safety CPU with a pause between power-off and power-on phase ³ 1.5 s.
18.	If a breakpoint is reached during debugging and you try to force a variable, then this variable is updated with the forced value only in the next safety CPU cycle.	The safety CPU is single-threaded.	This behavior is as designed.
19.	During project download to the safety CPU, the download window stays with 0 bytes of downloaded code forever or an error message pops up.	"Enable debug" parameter was set to “OFF” for the safety CPU and this configuration data was downloaded to non-safety CPU.	Set "Enable debug" parameter to “ON”, generate a new configuration and download project to non-safety CPU. New project code can be now downloaded to the safety CPU through AC500-S Programming Tool.
20.	Unable to log in to the safety CPU after logout.	Too fast log in to the safety CPU after logout.	Wait a few seconds (~ 5 - 10 s) after logout from the safety CPU before you perform log in to the safety CPU.
21.	Diagnosis message with error severity level 3 and error text "Measurement underflow at the I/O module" appears in non-safety CPU diagnosis system despite the fact that overcurrent and not undercurrent was observed for the given AI581-S input channel.	The internal detection mechanism is not always able to differentiate between over- and undercurrent because the overcurrent is often followed by undercurrent effects in AI581-S electronics.	There is no remedy for this problem yet.
22.	"Enable debug" parameter = “ON” was set for the safety CPU and correctly loaded to non-safety CPU. However, one still cannot debug on the safety CPU.	Safety projects on your PC and in the safety CPU are not the same. You may get also the following message window with the text: "The program has changed! Download the new program?".	Download your safety project from your PC to the safety CPU and debugging shall be possible now.
23.	In AC500-S Programming Tool, after using menu item “Online Reset”, the safety CPU goes to DEBUG STOP state (non-safety mode). Safety I/O modules go to module passivation state. If you log in to the safety CPU, then you can see OA_Req_S = TRUE bits in PROFIsafe instances of F-Devices. The safety application is not executed by the safety CPU, but you still can set OA_C = TRUE for F-Devices and they will go to RUN mode. The safety CPU remains in DEBUG STOP state (non-safety) all the time.	PROFIsafe F-Host does not run in fail-safe mode after using menu item “Online Reset”.	This behavior is as designed in the safety CPU. ⮫ “Description of safety CPU module states”
24.	Error message "Error in configuration data, safety PLC cannot read configuration data" is available on the safety CPU.	Downloaded configurations on non-safety CPU and safety CPU do not fit to each other. No boot project is loaded on the safety CPU.	Download valid configurations, as part of boot projects, on non-safety CPU and the safety CPU, respectively, and make sure that they fit to each other. Download a valid boot project on the safety CPU.
25.	UP LED = OFF on the safety I/O module.	The internal fuse on the safety I/O module has blown because of an overvoltage > 35 V DC. This can be caused, for example, by an impermissible hot swapping of the safety I/O module, etc.	Replace the module.
		Safety I/O module is not properly positioned on TU582-S terminal unit.	First de-energize the PLC. Then press the module with a force of at least 100 N into the terminal unit to achieve proper electrical contact.
		No correct power supply connection at UP and/or ZP terminals of the safety I/O module.	Correct UP and ZP wiring. ⮫ Electrical connection for DI581-S ⮫ Electrical connection for DX581-S ⮫ Electrical connection for AI581-S
26.	The BITS input of the SF_CRC_INIT function is set to any value from 1 to 7. If the functions SF_CRC_INPUT and SF_CRC_FINISH are used later in the safety application program, the result of the CRC calculation will be invalid.	Only BITS input values from 8 to 32 are supported by the function SF_CRC_INIT.	Change the BITS input values to the range of 8 to 32 for the function SF_CRC_INIT.