PLC 5/40 E


Thread Starter

Hemal S Joshipura

Dear Listers,
In PLC 5/40 E system I am having a doubt. For remote I/O communication we need to have ASB card(s). In case of ASB hang how can I reset it without shutting it off ?


R A Peterson

the normal way is to set the ASB dip switches so the CPU can automatically reset it. otherwise you can wire a remote PB into the asb to manually reset.

Michel A. Levesque, ing.

To reset an ASB is a simple game of bit toggling.
You must first configure a diagnostic file for the RIO channel. Then you can use Inhibit, Reset and Fault bits (in diag. file).

When a Fault is detected on a rack you set the Inhibit bit for that rack, then you set the Reset bit for that rack. This clears the rack Fault bit.
You then reset the Reset bit and reset the Inhibit bit. This should allow your rack to restart.

Good Luck.

Michel A. Levesque eng., mcp
Directeur Bureau Montreal
AIA Inc.
[email protected]

Terry Ziegenhorn


I believe that it is terminal 11 & 12 on the ASB that you short out. That should reset your remote I/O.


Hemal S Joshipura

Well I have tried to reset it through terminal 11 and 12 by shorting it. But I couldn't reset it.

Bob Desrochers

There is a dip switch selection on the chassis backplane which determines if the PLC can automatically reset the asb or if terms 11 + 12 are to be used. Double check your backplane switch settings and be sure that your literature is for the *exact* revision of asb that you are using.