TheWaterboy
Lifetime Supporting Member + Moderator
Envision following simple rungs
The intent in the first rung appears to be an effort to save wear of the output module and the interposing relay.
The attached device is not a lamp or other device that needs to have its input held to maintain position so that's out of the equation.
My counter argument would be that it is more difficult to troubleshoot when facing the PLC since you cant tell what outputs are set.
How common is this practice and is it worth doing? I would like to stop doing this if its just an old school technique that is no longer necessary but if there is some validity to it I would like to hear about it.
Thanks in Advance
Code:
Input [XIC]-------Valve Open STATUS [XIO]-------Valve Open COMMAND [OTE]
Input [XIC]-------------------------------------Valve Open COMMAND [OTE]
The intent in the first rung appears to be an effort to save wear of the output module and the interposing relay.
The attached device is not a lamp or other device that needs to have its input held to maintain position so that's out of the equation.
My counter argument would be that it is more difficult to troubleshoot when facing the PLC since you cant tell what outputs are set.
How common is this practice and is it worth doing? I would like to stop doing this if its just an old school technique that is no longer necessary but if there is some validity to it I would like to hear about it.
Thanks in Advance