where to get non-inverting opto22 type modules?


Thread Starter

mike kilroy

I need an opto22 style rack with 13 inputs and 3 outputs, but they must be non-inverting inputs.

ie, sourcing rather than sinking on the output side.

Why? my servo drive requires +24Vdc to turn on the inputs, so the normal negative true logic of most opto22 style modules and racks won't work. I cannot change my input meanings; I am bringing in a BCD word, and the inverse of it is not a valid command so I must have sourcing inputs.

Check Opto22. Their G1 and G4 style modules, both inputs and outputs, can be connected for sinking or sourcing. They also have relay modules for contact outputs.

Guy H. Looney

G4-ODC5-SRC modules will get you what you need. You could also use their
SNAP modules if space is a concern: SNAP-ODC5-SRC.
I'm not sure if I read your question right.

If you are talking about the single point modules, sourcing or sinking the output side (screw terminals) is just a matter of how you wire it. You have both terminals and they're not common to anything else.

In Other Words:

( I may have the odd/even terminal polarity for the Opto module incorrect here, if so, just reverse them)

To get sinking behavior, wire +24V to one side of the load, the Odd terminal to the other side of the load, and Ground to the Even terminal.

+24V ----- (Load) ----- [ODC5] --- 0V

To get Sourcing behavior, wire +24V to the Odd terminal, The even terminal to one side of the load, and ground to the other side of the load.

+24V ----- [ODC5] ----- (Load) ---- 0V


If, on the other hand, you really want to invert your inputs, you probably can do some kind of pullup or pulldown wiring along these lines:

+24V ---- <resistor> ---------- [ IDC5] ----- 0V
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Any help?
Can't you wire them either way? I know that you can wire the Opto 22 G4
series outputs for sinking or sourcing. They emulate a contact in series
with the load. It depends whether you put the opto module before or after
the load, which is your drive's input. With the newer Opto 22 Snap
outputs, you must order them as sinking or sourcing. I am not sure about
the old style. Use the new style anyhow, as they are much smaller. The
G4PB24, G4ODC5 and G4IDC5 are very nice.

All of Opto 22 datasheets are available for download from their web page also.

Bill Sturm