Using PCI-6521 to control SQD Contactors

[LabAvatar]

Good Day,
One of my vendors intimated to me that they can use a PCI-6521 to control On/Off functions.  My question is, what is need to make this happen?  We are looking at Square D 600V 120A contactors.  I don't know how to make the physical connection to the contactors from the 6521.  Does anyone have any experience doing this?

[Now_With_Underscores]

Hello LabAvatar,

If you're trying to run external relays, I'd highly recommend looking at our PXI-2567, which is designed to handle the current demand of large relays (contactors).  The 2567 can drive up to 600mA per channel across 64 channels with an external power supply.  

We could use the 6521, but the digital output current is very low.  For maximum current, we could connect the relay to +5 and then to digital out X.  This allows us to sink current into the DO line.  We could use a voltage follower on output of each digital line to provide the current neccessary to energize the relay coil. In this case, we could go from DO to ground.  Voltage followers are cheap and can be purchased at most DIY electronic stores.