L32e cpu hold last input data if 1734 aent,ib8 or ob8 communication failure

[naag_slet]

Hi to All,
Actually today i had tried with this concept,but no result..
i have L32E cpu and 1734AENT with IB8 and OB8(in the testing kit)
please have a look into the attached RSLOGIX5000 file and have a look the programme in the main routine if wrong please suggest the right programme..
My requirement is when IB8 OR OB8 OR 1734AENT fails input status has to set back to '0'.INSTEAD OF SHOWING LAST STATE.

Many Thanks in advance..
Naag.

 

[daba]

One way to achieve this is to write code to clear the input data when a module fault is reported.

 

[Ken Roach]

Creating code to set the Input data points to zero in the event of a communications failure is only useful if all zeroes is not a valid state of the input module.

The Module Status is a specific and exact indication of the I/O state, while an "all zero" value would only be an inference that the network connection or network adapter had failed.

The ladder logic you showed is very similar to the way I do it; I usually combine those functions into single rung or use Structured Text.

 

[naag_slet]

Thanks Kenroach,
it working fine and i am planning to implement this.
will get back to you with the final results