S7400-Red-IO Modules Error

Dear Team,

I am encountering an unusual issue with my S7-400 System, which serves as a safety system operating in a redundant configuration. Following a recent power outage and subsequent restoration of power, all of my IO Modules have ceased functioning properly, with each displaying an error and the Err LED flashing red.

Despite re-downloading both the hardware and software, the controllers now operate in a Redundant (Primary standby Configuration), yet all IO modules remain in a fault state. Specifically, for AI Modules, all channel Fault LEDs are illuminated red, rendering me unable to retrieve any data from the field.

Upon attempting to assess the Module information, it consistently indicates a Module Error, while the IO Diagnostic reveals a "Supply voltage too high" message, despite the voltage levels falling within the acceptable range.

Could anyone kindly offer recommendations on how to proceed in resolving this IO module error and restoring the ability to successfully retrieve field values within my system?

Attached, please find pertinent images and controller diagnostic files for your reference.

Thank you for your assistance.

Best regards,

Usman

AutoGen_1094521

Dear Team,

I am encountering an unusual issue with my S7-400 System, which serves as a safety system operating in a redundant configuration. Following a recent power outage and subsequent restoration of power, all of my IO Modules have ceased functioning properly, with each displaying an error and the Err LED flashing red.

Despite re-downloading both the hardware and software, the controllers now operate in a Redundant (Primary standby Configuration), yet all IO modules remain in a fault state. Specifically, for AI Modules, all channel Fault LEDs are illuminated red, rendering me unable to retrieve any data from the field.

Upon attempting to assess the Module information, it consistently indicates a Module Error, while the IO Diagnostic reveals a "Supply voltage too high" message, despite the voltage levels falling within the acceptable range.

Could anyone kindly offer recommendations on how to proceed in resolving this IO module error and restoring the ability to successfully retrieve field values within my system?

Attached, please find pertinent images and controller diagnostic files for your reference.

Thank you for your assistance.

Best regards,

Usman

 Hi Mate

Power fluctuation affects a PLC CPU tremendously if there is no power backup system. It is recommended to have an uninterrupted power backup system for AT LEAST all the control voltages. This smart approach will protect the CPU and its modules from power fluctuation negative impact. 

The question now is what was restored after the power outage restoration what has changed? was there any change of equipment?

If yes. What was changed was it an Apple for Apple?

if no. What has changed and how will it impact the CPU  and its components

Accordingly, the picture shared for the Simatic ET 200 PS HA IM155-6 PN HA shows two peculiar faults

1. Supply voltage missing

2. Supply too high.

We can check the voltage connection of each unit in racks 4 up to 7, ensuring the availability of the required voltage of 24V DC.

If the voltage is ok which is doubtfully then we can follow the instructions on page 29 in the manual for Error Led

et200ha_im_155_6_pn_ha_en-US_en-US.pdf - SIMATIC ET 200SP HA Interface Module IM ... - ID: 109802841 - Industry Support Siemens

Let us know the outcome of troubleshooting.