The Allen-Bradley 1794-IE4XOE2 is a combination I/O module. This module is part of the Flex I/O product family that are popularly used to implement distributed I/O architecture. The 1794-IE4XOE2 features the combined capability of analog and input channels as this module comes with Four (4) single-ended, non-isolated analog input channels and Two (2) single-ended, non-isolated analog output channels.

The analog input channels are configurable to receive analog input signals such as 0-20 mA and 4-20 mA signals and 0-10VDC and +/- 10VDC voltage signals. It has a built-in Analog to Digital converter (ADC) using the successive approximation method. Each channel has a conversion rate of 256μs with step response to 63% of 9.4 ms for voltage and 18.2 ms for current. It has an absolute accuracy of 0.20% Full Scale @ 25°C. This module saves the converted data into left justified, 16 bit 2s complement data format.

The analog output channels are capable of providing 0-20 mA and 4-20 mA signals as well as 0-10VDC and +/- 10VDC. The analog circuitry of the 1794-IE4XOE2 combination analog I/O module features a built-in Digital to Analog converter (DAC) using Pulse width modulation conversion method. The converted data is provided with an accuracy of 0.133% Full Scale @ 25°C and 0.425% Full Scale @ 25°C.

The 1794-IE4XOE2 requires use of a terminal base unit. This terminal base provide the terminal connection points as well as the backplane interface pins. Appropriate terminal base unit for use with the 1794-IE4XOE2 are 1794-TB2, -TB3, -TB3S, -TB3T, -TB3TS Terminal Base Units.

The 1794-IE4XOE2 module contains 4 single-ended and non-isolated inputs. The resolution for unipolar inputs is 12 bits while the resolution for bipolar inputs is 11 bits. The data format is left-justified 16-bits 2’s complement. The conversion type supported by the 1794-IE4XOE2 module is successive approximation conversion. The input current terminal is selectable between 4 to 20 milliamps or 0 to 20 milliamps. The input voltage terminal is selectable between ±10 Volts and 0 to 10 Volts. The normal mode rejection ratio for the voltage terminal is -3 dB at 17 Hertz and -10 dB at 50 Hertz. The normal mode rejection ratio for the current terminal is -3 dB at 9 Hertz and -15.3 dB at 50 Hertz. The input impedance for the voltage terminal is 100 kiloohms and for the current terminal, it is 238 Ohms. The 1794-IE4XOE2 module contains 2 single-ended and non-isolated outputs. The conversion type is pulse width modulation. The current load on the voltage output is 3 milliamps (maximum). The dimensions of the 1794-IE4XOE2 module are 1.8 x 3.7 x 2.1 inches. The power required is 24 Volts DC (19.2 to 31.2 Volts DC) with 70 milliamps of current at 24 Volts DC. The maximum thermal dissipation is 13.6 BTU/hour and the maximum power dissipation is 4 Watts at 31.2 Volts DC.