Siemens S7

[baznew]

Hi
I have issue where I cannot see any inputs in my plc program.
Im using CPU317-2 dp. im360 module, then input modules.
I can view the modules online and there are no errors with them.
however, inputs are present at the front of the cards, but they are not "seen" by the processor.

Anyone have any ideas?
thanks

 

[S7Guy]

Don't be insulted, but let's check the easy things first: Are you sure you are monitoring the addresses that are assigned to those particular cards? Also, double check the common connection on the cards. Possibly the leds themselves are lighting up but don't make it to the card itself. That is possible with output cards, but I'm not sure about input cards.

 

[baznew]

No Offence taken.
Ive checked all the cards (removed from rack) all connectors are OK. The CPU does recognise the modules, diagnostic online states "module ok and available."
The addresses look ok.
Im not sure if there is some hidden mapping im missing.
Looking through the manual, there doesnt appear to be any OB that I need for Input modules to register their inputs in the process image.
Still searching online and through manual, but nothing comes to light.
Thanks anyway

 

[S7Guy]

Have you tried entering the addresses in a VAT table? I'm not sure what range of addresses you are using or if you even built this project, but maybe the process image table was set to some weird range. If the addresses are invalid, it will displayed as such in the VAT table, and we'll at least have a clue of what to look at.

 

[PeterW]

You can status the I/O directly from the card in hardware profile, might be an idea to start there, that will also show your the sddresses you should be using.

If you have assigned symbols to the I/O, these should be checked there as well.

Also I seem to remember some thread in the past where the electrical wiring was a problem, like the +/- power to the card connected or something like that. The voltage direct to the in put will light the LED, but if the cards main power is not connected it won't get through.

 

[baznew]

Thanks for the replies.
I have just tried a different processor, I'm getting exactly the same result, no Inputs.
All the outputs are working and can be set in the VAT table.
I'll recheck the voltages and wiring because this seems like it could be there.
thanks again

 

[MURDERER]

Thanks for the replies.
I have just tried a different processor, I'm getting exactly the same result, no Inputs.
All the outputs are working and can be set in the VAT table.
I'll recheck the voltages and wiring because this seems like it could be there.
thanks again

That should be on supply voltage.

 

[RolfB]

That should be on supply voltage

it seems so.
I don't know which type of inputcard
you uses, but you should examine the wiring again
for the common-wire (0V) on Pin 20 (40).

regards
Rolf

 

[Prince]

Just as a note:

When you say that the IO addresses are OK do you mean the Drawings or the Hardware configuration?
I have seen many instances that people change the Hardware configuration without changing the drawings