Hardware fault (I/O module)

Siemens PLC & VFD Error plc

Model: S7-1200/1500 | Code: 7900

Applicable Systems
S7-1200 S7-1500 S7-300 S7-400 LOGO! SINAMICS

Symptoms

I/O module reports hardware fault.

Possible Causes

Module hardware defect, module not properly seated, or electronic component failure.

Troubleshooting Steps

Reseat module, check backplane connector, replace module if defective.

How to Reset

Replace module and restart

Related Siemens Fault Codes

Source: Siemens S7-1200/1500 system diagnostics

Category: PLC & VFD