Help required for Siemens S7-200 anlog input module

Dear friends,
Presently we are commissioning S7-200 CPU 226 based machine in our soap plant. The configuration is CPU 226 + EM235 + EM232 + EM 231.
EM 231 is the last module attached to PLC. The problem is 24V LED of this module is not glowing & this module is inactive. I have checked 24 V at connector, it is there. In all other connected modules 24 V LED is glowing. When I powerup PLC for once SF LED ( Red ) glows for a sec & then switches off.
On further checking I observed that there are 8 nos. DIP switches on this module & all are in OFF position. In EM235 ( module next to CPU) there are 6nos of DIP switches & switch no.1 & 6 are ON rest are OFF. Is this got any connection with non glowing of 24 V LED on EM 231 or the module has become faulty & needed to be changed.
Kindly advice
Regards,
Neeraj

Hello neeraj;

If you have 24 V DC at the L+/M contacts and no LED, then either you have blown a fuse (solid-state fuse, on the circuit board) or your module is shot.

You can confirm this status by reading SMB12 and 13: these are Module ID (SMB12) and Error code (SMB13) for module 2 (3rd IO module on the bus).
Here are they can be decoded:



The dipswitches are used to configure the input channels of the analog module:



Hope this helps,
Daniel Chartier

I wish I could see the registers but I dont have the software to go online. The supplier has already couriered the new module from Italy but the only thing bugging me is why all the DIP switched are off.