The IC697ALG440 Current Input Expander Module belongs to the Series 90-70 Programmable Logic Controllers product line manufactured by GE Fanuc. It has 16 current inputs with a 4 to 20 milliamps input current range. The IC697ALG440 Current Input Expander Module must be used with a base converter module and a voltage expander module to create an analog input subsystem for a programmable logic controller. The users can use any mix of these expander modules with the base converter to have a system with a maximum of 120 input channels. It converts a digital form of a signal into an analog form and represents the converted data in the 2’s complement format. Some of the features of the expander module include status indicator LEDs, error detection facilities, expander channel response detection, and module health diagnostic facilities.

The IC697ALG440 Current Input Expander Module has an analog multiplexer to connect the inputs to the analog-to-digital converter. The whole connecting process is a switching circuit and it connects the inputs one at a time. Terminals 36 and 38 of the base converter module can be used to connect the analog expansion signal. For the differential data bus, the user can select terminals 37 and 39 which act as serial communication ports. Make sure to consider the polarity before connecting the cables. It is necessary to connect the shield ground to terminal 35 if it is shielded. However, shielding is not compulsory, it is optional. The IC697ALG440 Current Input Expander Module must be located in the same rack as the expander modules connected to it so that the modules are adjacent to each other.