What is the max current output of an NI 9472?

[kent.wedeking]

I'm looking at using an NI 9472 Digital Output module to control 6 solenoids on a test setup I'm building.  Solenoids are 24V, 30W devices, so I'm looking at needing close to 2A when they run.  Only 1 solenoid will be running at any given time.  I see the max current per channel on the module is 750mA, but I'm was wondering if there was a max current output of the module instead of just 1 channel?  Maybe I'm grabbing at straws, but I figured it's worth a shot.     Kent

[TheWoost]

Hi Kent,

There is no specification on the maximum current output of the module because that module is designed for per-channel use.  Based upon your question, it sounds like you are wanting to use parallel digital outputs on the 9472 to obtain the necessary 2A of current.  This method of obtaining more current from the module is not officially supported or tested by National Instruments, but this implementation may work for your application anyway. The issues I foresee with wiring two digital outputs in parallel is that if your digital outputs are at different potentials (i.e. one line is turned on and the other is turned off) for any amount of time, current will flow back into the module and likely damage it.

Because you are already needing an external power supply for this application, you may consider the NI-9481 Relay Module if your external supply is capable of sourcing the 2A of current needed for your solenoid.  You would need 2 of these modules to control 6 solenoids, but that may work for you.  For more information about this module, please go here.

Regards,
Andrew W
National Instruments

[AnalogKid2DigitalMan]

Strongly suggest the use of protection diodes directly across the solenoid coils or other suitable methods to provide surge protection for the DAQ card. When you turn power off to the soleniod a large transient voltage will be created that will likely damage the DAQ's electronics.