1771-OFE2 Allen-Bradley analog output module

The Allen-Bradley 1771-OFE2 is an analog output module from the 1771 Product family. It features Four (4) individually isolated analog output channels that delivers 4-20 mA output current signal. This module is typically used for controlling Final Control Elements (FCE) such as Variable Frequency Drives (VFD), Dampers, Louvers, Valves and other equipment and devices. It may also be used to implement the output of a Proportional + Integral + Derivative (PID) controller to implement automatic control of an analog loop. Additionally, this module may also be used to transmit signals to measuring, receiving and recording elements such as Signal Isolators, signal converters, panel meters, data loggers and other similar instruments.

The 1771-OFE2 is installed to any 1771 I/O chassis. It can serve as local and remote I/O module of a PLC 5 controller. It occupies a single slot of the chassis and uses the 1771-WC field Wiring arm. Each channels has rated isolation of 850 VDC for 1 Second while the Digital to Analog Converter (DAC) settling time is maximum of 0.8 ms. It has backplane current draw of 1.50 Amperes, power dissipation of 7.9 Watts, Thermal Dissipation of 26.9 BTU/hr and adjacent slot power maximum dissipation of 10 Watts. When wiring output devices to the channels of this analog output module, use 12 Gauge stranded or solid wire with insulation thickness of 3/64 inch or 1.2 mm. Recommended cable is Belden 8761. During installation to the chassis, ensure that module keying is set at 10 and 12 / 26 and 28. Tighten wire termination with force of 7-9 lbs/in.

The 1771-OFE2 module has 4 output channels with isolation of 1000 Volt individually-isolated differential outputs. It requires a power of 1.4A at 5 Volts which is supplied from the I/O chassis backplane, thus no external power supply is needed. It has a channel update time of 8 milliseconds per 4 channels for BCD and 1.6 milliseconds per 4 channels for Natural Binary. It has a maximum power dissipation of 7.9 Watts and maximum thermal dissipation of 26.9 BTU/hour. The 1771-OFE2 includes a wiring arm to replace the module without disconnecting the wires. It can be installed in any slot in the 1771 I/O chassis and keying bands must be snapped between pins 10 to 12 and 26 to 28 for fixing that slot. The 1771-OFE2 module can convert raw data into engineering units such as degrees Celsius, degrees Fahrenheit, gallons/minute, and pounds/square inch. For diagnostics, it performs a self-check at start-up. If a fault occurs, the red fault indicator LED lights up and the green power status indicator LED remains off. The 1771-OFE2 has 1500 Volts of optoelectrical isolation that protects the system from overvoltage.