The West instruments linear output plug-in module, slot 2 or 3 is designed for West and Partlow plus series controllers. When applied current of 0mA to 20mA with parallel 500ohms resistor it gives an output of 0V to 20V and vice versa. It is often used as either a cool output on a heat/cool application or a retransmission output.
Note:
These boards cannot be used with the older N series controls.

Accuracy +/-0.25% at 250ohms
Control outputs have 2% over/underdrive applied