The 1771-IF04 module is an analog input module manufactured by Allen-Bradley/Rockwell Automation in the PLC 5 product line. This module is an intelligent module that is used to interface between the analog inputs and the PLC processors through block transfer programming. The module uses up to 12-bit resolution and it provides the necessary analog to digital conversions, and the reverse is also true, thus enabling the interface of analog signals with the PLC data table values. The applications of this module include pressure sensing, level sensing, temperature sensing, and flow metering applications. The 1771-IF04 module operates on a voltage range of 0 to 10 Volts DC and it has 8 or 16 single-ended inputs, and a current range of 4 to 20 milliamps, 0 to 20 milliamps, or -20 to 20 milliamps.

The Allen-Bradley 1771-IF04 analog input module features a maximum current of 1.7 milliamps AC/DC in the off-state, a backplane current load of 1.3 Amps at 5 Volts DC, and a channel update time of 8 milliseconds for 8 channels as well as 12-bits plus sign resolution. It comes with a typical delay time of 24 milliseconds in AC voltage in an on/off-state, 10 milliseconds in DC voltage in an on-state, and 20 milliseconds in DC voltage in an off-state. Other specifications of the 1771-IF04 module include a 1771-WB wiring arm that is used in the module to eliminate the need for disconnecting all the wiring. The module also requires a single slot to enhance the installation of the I/O chassis and keying in bands for accurate installation between pins 6 and 8 and pins 22 and 24 for the left connector and right connector pins 4 and 6 and pins 32 and 34.