As u know SIEMENS CPU 928B has an SI1 and SI2 leds in front of card.when the cpu in stop mode only BASP led should be ON.In our application we are not use SI1,SI2 (Serial Interface 1,2).

Problem is this :
CPU is in STOP state and BASP, SI1, SI2 leds ON.But in normal conditions only the BASP led should be ON when the CPU 928B in STOP state.Because of the SI1,SI2 leds ON, i didnt reload my PLC program and also i didnt restart.
Is this problem result of electronic component malfunction problem or CPU928B data loss(Loaded from SIEMENS not user program) ?

 

Hello

When you switch the 928B to run both SI1 and SI2 LEDs should go out, SI2 requires a sub-module to be present for operation, and firmware on the EPROM, to activate it, if no sub-module is present this LED should extinguish immediately on start up. The SI1 LED should extinguish a few seconds after start up, to allow the comms link to be established in the EPROM firmware, if both LEDs remain lit, the Siemens manual states that there is either a faulty EPROM (unlikely) or the EPROM data is corrupted or incorrect to establish the comm links. You will need to confirm that the EPROM data is correct for the intended use of SI1 and SI2 ports.

Regards

Peter

 

i have the same problem. SI1 SI2 ON.
also introduced another cpu 928B and the same appears SI1, SI2 ON
I ask please help me solve this problem. (i have 928 and 928B cpu)

I introduced other RAM and EEPROM and continuous failure. lit CPU without memory and SI1 SI2 failure and remains on BASP

please help me

>When you switch the 928B to run both SI1 and SI2 LEDs should
>go out, SI2 requires a sub-module to be present for
>operation, and firmware on the EPROM, to activate it, if no
>sub-module is present this LED should extinguish immediately
>on start up. The SI1 LED should extinguish a few seconds
>after start up, to allow the comms link to be established in
>the EPROM firmware, if both LEDs remain lit, the Siemens
>manual states that there is either a faulty EPROM (unlikely)
>or the EPROM data is corrupted or incorrect to establish the
>comm links. You will need to confirm that the EPROM data is
>correct for the intended use of SI1 and SI2 ports.