How to connect a quadrature encoder to an IC-3173?

[JKSH]

Hello,

I have an existing application that runs on a PXI, and talks to a quadrature encoder (a Sick DFS60B-TDPC10000 which can draw up to 170 mA).

My application uses a PXIe-6612 to read the encoder's signals. The PXIe-6612 also supplies power to the encoder via its +5V pin. The datasheet says that the +5V pin can supply up to 1 A current, which is plenty for the encoder.

I would now like to port the application to an IC-3173, but I'm uncertain about how to connect the encoder.

According to http://www.ni.com/pdf/manuals/375285c.pdf the encoder A and B pins should connect to Diff0+ and Diff1+ (pins 1 and 9) respectively. However, what about the power supply?

1. Do I connect a 5 V supply to V_ISO on the controller chassis, and then connect the "Isolated power voltage reference output" (pins 10 or 25) to the encoder's "Power Supply" pin?
2. The specifications say that I mustn't draw more than 50 mA at 5V from the individual "General purpose isolated output" pins. Does this also apply to the "Isolated power voltage reference output" pins?

Thanks in advance!

[JKSH · Accepted solution]

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@JKSH wrote:

1. Do I connect a 5 V supply to V_ISO on the controller chassis, and then connect the "Isolated power voltage reference output" (pins 10 or 25) to the encoder's "Power Supply" pin?
2. The specifications say that I mustn't draw more than 50 mA at 5V from the individual "General purpose isolated output" pins. Does this also apply to the "Isolated power voltage reference output" pins?

Answering my own question:

1. Yes, that seems to work.
   • I connected a ~28 ohm resistance between "Isolated power voltage reference output" (pin 25) and "Common ground reference for isolated inputs and outputs" (pin 11). I got 5 V 180 mA out of the system.
     
   • When I repeated the experiment between "Iso Out 7" (pin 44) and pin 11, the 5V output dropped to 0 as soon as the resistors touched the pins.
     
2. I didn't read the manual properly. http://www.ni.com/pdf/manuals/375284c.pdf says that I can draw up to 640 mA from the  "Isolated power voltage reference output" pins.