We are planning to use this with a 50 foot 6 conductor 20AWG Shielded copper wire connection.
Is there a limit to the length of the connection?
The control wires (CLK and RES) can be very long. The length of allowed cable length off the COM signals depends on the sensors you have connected. Consider the 50ft being added onto the length of your sensor cable.
Thanks JDavis my concern is we are using diodes for cryogenic temp sensors.
The relays in the multiplexer have 0.1 Ohm typical contact resistance. You also add in the resistance of the wires between the multiplexer and the datalogger. You are also adding capacitance. If capacitance is an issue, settling time can generally compensate for it.