The 24 VDC Positive/Negative Fast Input Module (IC670MDL644) provides a single group of

16 discrete inputs, which may be driven by positive or negative logic.

Power Sources

The module receives power from the Bus Interface Unit to run its own 5±volt logic. An

external 24VDC supply is needed to power the input devices.

LEDs

Individual LEDs (logic side), visible through the transparent portion of the module top,

indicate the on/off status of each input. The PWR LED is on when field and backplane power

are present.

Host Interface

Intelligent processing for this module is performed by the Bus Interface Unit or elsewhere in

the system. This includes configuring features such as input defaults and fault reporting. The

module has 16 bits (two bytes) of discrete input data. A Bus Interface Unit is required to

provide this input data to the host and/or local processor.