I want M-series DAQ to turn on and off a PC via power header

[NI_LV_82_User]

I want my M-series DAQ to turn on and off a PC via the power header.  My original thought was to use the analog output to drive a relay to open or shunt the header.  However, the M-series DAQ can only drive 5mA, and I am finding it hard to locate a small relay that operates at this current.  Any help would be appreciated.

[Dennis_Knutson]

I'm sure there are relays out there with low current requirements but there are also inexpensive relay drivers. I've used the ULN2xxx series.

[NI_LV_82_User]

I have found a few low current relays, but it seems these may be on the edge for what my DAQ's (M-series 6281 & 6251 and X-series 6361 & 6363) can drive (5mA) output max.You (Dennis Knutson) mention using a ULN2xxx series relay driver.  Do you have to supply external (not from the DAQ) voltage/current to this device?  Can you elaborate on the fundamentals of using a relay driver, please?My goal is to have each breakout box (SCC-68) have a set of wires (2) that I can attach to the power pins of a PC motherboard and turn the system on and off programmatically with LabVIEW.  I have a number of NI chassis, each populated with a number of DAQ's (types listed above) and I would like to have each SCC-68 have the ability to control a separate PC.  Because of this, I would like to minimize the amount of external wiring (and power) going to and from the SCC-68.  Ideally I would like to mount a single relay on the breadboard area of the SCC-68 and control it by the AO (or DO, if that is better... not sure…?) pins and routed out to the PC.If that is not doable, then understanding and adding a relay driver may be the solution.

Thanks for any help anyone can provide!

[Dennis_Knutson]

I don't remember offhand what the +5 output current of the DAQ board is. I've always used an external supply. A simple wall transformer that you can pick up at places such as Radio Shack works fine. You might be able to use the DAQ card but that would depend on the number of drivers being used and the current required for each relay

The relay drivers are available as inverting and non-inverting outputs. Typically, you just connect a digital output to one of the inputs and the output is connected to the relay.