S7-400(Communication failure with IM151)

[zare.v]

plc s7 400 communication

I have recently faced a problem for our PLC(S7-400) which controls our Electro-compressor.(you can find our configuration in this address
Our PLC has communication wit site via two paths, one is via "Fiberoptics Module Profibus"(OZD Profi 12M) and the other is via ET200 S(IM151: 6ES7 151 -1AA02-0ab0). The problem is the IM151 communication failure with PLC, On IM 151 the "SF" led is lit and the "BF" led is blinking, on CPU the "BUS2" is also blinking.
I reloaded the configuration file into PLC, replaced the IM151 with a healthy one, even changed the interconnection cable but the problem was not fixed.
I would greatly appreciate if someone can advise me on resolving the matter.

 

[murali_dece]

im151 blinking

we are using the same plc s7 400,in our cement plant.bus fault occurs due to bad end termination of profibus cable.profibus cable is parallel to all IM 151 modules but profibus cable at IM151 module end should be terminated (i.e physically last IM module in profibus network). end termination is done by puting the dip swith "on" which is provided on profibus connector, remaining all profibus conectors dip switches are in "off" position other wise bus fault will blink.

system fault will occur when all modules which are assigned in plc project are not recognised by the plc. both problems are related,