The 61C501 is an Input Module created by Reliance Electric. There is a strong possibility that the 61C501 was also under the Baldor Reliance and/or Asea Brown Boveri product lines. None of these companies are still making the 61C501 and it may be a little hard to find now. However, AX Control does attempt to have this item in stock.
The 61C501 is an AutoMax Digital I/O Card Module. This module has a 16-point high-density digital I/O connection. It has isolated commons that have been placed into groups of four. It has keyed connectors and a 2500 V isolation. It has an AC current with a 115-voltage. It has an operating voltage of 132V RMS, 92V RMS turn on, and 22V RMS turnoff. This card has a maximum input delay of 35msec @ 50 Hz, a 26msec @60Hz, and 4 inputs per iso. common.
The 61C501 typically provides the simple on/off commands from devices like pushbuttons or selector and limit switches. It can also affect motor starters, solenoids, and indicators in this way.
This module had a printed circuit board and faceplate that is contained in a protective chassis. It has 20 input connections and a total of 16 LED indicator lights that are numerically labeled 0-15. The 20 input connections are labeled 0-3,C1, 4-7, C2, 8-11, C3, 12-15, and C4. This module can be mounted onto a storage rack assembly. To do this find a slot on the rack that is open and slide the card into it, connecting it to the card slots on the backplane of the rack. After that, you can use two screws to further secure this module.