About the 45c46
The 45c46 is a Dual Voltage Comparator Input Module. It was initially created by Reliance Electric for its AutoMate series of programmable controllers. Baldor Reliance and ABB may have also sold this module, but none of these companies are still offering support for the 45c46. AX Control does still try to keep this module in stock as a new surplus or refurbished part.
The 45c46 is part of a series of I/O modules that are typically optically isolated from field signals. They are high-threshold circuits that will not turn on until a certain voltage has been reached. This is a security feature that will keep false signals from interfering with the modules. The voltage comparator module specifically has the ability to send the results it obtains to its processor as it compares two analog voltage signals. It has the ability to make less-than and greater-than signal comparisons. It can also compare a signal that is coming to it externally and compare its voltage to a user-determined preset voltage value.
The 45c46 is a small L-shaped part. On its faceplate, it has two small dials. One is labeled INCR Reference and the other is labeled INCR Dead Band. There are also two LED indicators that are labeled ODD-HI and Even-HI. There is also a Phillips head screw in the center of the faceplate. On the back of the module are a four-pronged plug and a slot that can be plugged into a card slot. It has a maximum input of 10 VDC. The 45c46 can be plugged horizontally into the digital I/O rail assembly system 45C1.
