Siemens S5-928B

Hi

i have a problem before with the PLC power supply,and i have got it changed by new one,upon power up the system again the cpu goes normal to run mode
but while using to start the operation from the HMI screen (for example to start a motor) no have any action at all,so any one have experience with same problem before i will be grateful if you share it

The PLC battery which backs up the RAM in the CPU is located in the power supply. Which means, if you remove either the CPU or the power supply, you will lose any information stored in RAM.

If you have an EPROM or EEPROM installed in the CPU, then it should copy its information to the RAM upon first power up after replacement. First, try a Cold Restart from the S5 programming software, and if that doesn't work, do an overall reset (key switch procedure on the CPU.

Warning: the overall reset will clear the RAM in the CPU, and copy the contents of the EPROM or EEPROM to the RAM of the CPU.

1. Switch the mode selector from RUN to STOP.
Result: The CPU is in the stop mode. The STOP LED is lit continuously.

2. Hold the reset switch in the OVERALL RESET position; at the same time, switch the mode selector from STOP to RUN and back to STOP.
Result: An OVERALL RESET is requested. The STOP LED flashes quickly.