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PCI 7342 digital output

PCI 7342 digital output

I am using PCI 7342 motion controller and UMI7772. There are 6 relays in my system, which are 24Vdc coil voltage and 37mA coil current for each. Can I use digital output on PCI 7342 through UMI7772 to drive these relays?
PCI7342's digital output is 0-5V, 24mA, but through UMI7772, I can get 5-30Vdc, 100mA output. Am I right? I am not sure 100mA is total or for each output.

Thanks for reply.
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Re: PCI 7342 digital output

The 7772 can source 100 mA per digital output line on the eight sourcing DOs. I agree that this not clearly enough specified in the UMI-7772/7774 user manual.

Best regards,

Jochen Klier
NI-Germany
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Re: PCI 7342 digital output

Don't forget that a relay is basically an inductor and therefore the inrush current can be somewhat higher than the rated current. But I don't think that this might cause problems in this application.

In any case you should connect a breakdown diode in parallel with the relay coil to keep off inducted voltage from the 734x outputs, or some other snubber circuitry.
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