1734 Point IO for 24VAC

[pal]

The output cards with OW in the code are relay types and will handle AC voltages . I use them quite often for 24v ac . I normally use 24v dc for the inputs , however if you must use 24 vac for the inputs , you could try a resistor , diode in series with a 24v zener diode/capacitor/resistor in parallel to ground . Take the input to a 24v dc card from above the zener . A bit cumbersome , but it will do the job .

Paul

 

[the_msp]

Interesting Paul. I assume the highest density then is 4 O/P per card?

 

[pal]

I'm out of my comfort zone here Patrick , virtually all our AB PLC's are CompactLogix , but the catalog shows an 1756-OW16I module . If it's the same as Compact , then it is wider than the standard modules to accomodate the extra terminals .
Incidentally while I was looking for the biggest OW module , I came across the 1756 IC input card which is intended for 48V dc . Since rectified 24vac falls within it's operating voltage , the zener diode in my previous message would not be needed .

Paul

 

[TheWaterboy]

Building the equivalent of a dc power supply on each input would probably work, but I wouldn't want to leave something like that in a clients machine.
I'll deal with an interposing relay. Thanks to all for the info.