The Allen-Bradley 1794-IE8 is a component module of the Flex I/O product family. This module is an Analog input module, used with Flex I/O communication adapters and terminal bases for implementing Distributed I/O architecture.

Using the module’s Eight (8) single-ended, non-isolated, user configurable channels capable of receiving 0 to 20mA, 4 to 20 mA, +/- 10VDC and 0 to 10 VDC input signals, this module is capable of interfacing instruments such as field transmitters, analog indicating instruments, recorders, process loop controllers and other analog instruments that generates the compatible signal ranges.

This Flex I/O analog input module has a resolution of 12 bits when configured in unipolar mode and 11 bits plus sign for bipolar mode. It uses a successive approximation conversion and save the converted data in data format of eft justified, 16-bit 2s complement. It has a conversion rate 256?s on all channels with absolute accuracy of 0.20% Full Scale @ 25°C and accuracy drift of - 0.00428% Full Scale/°C for Voltage and 0.00407% Full Scale/°C for current input. This module does not require calibration.

The 1794-IE8 requires an external Power supply voltage range of 10.5-31.2VDC with nominal supply voltage of 24VDC. It requires a supply current of 60 mA. It requires use of terminal base for mounting and interfacing to input signal wiring. Compatible terminal bases are 1794-TB2, 1794-TB3, and 1794-TB3S, 1794-TB3T and 1794-TB3TS. Only one terminal base is needed by the module.

This Flex I/O module is compatible with Flex I/O communication adapters such as Ethernet, ControlNet, Remote I/O adapters.

No calibration beyond the factory setting is required for this module. It measures 3.7 x 2.1 x 31.8 inches and can be installed to a DIN rail or directly panel mounted. The 1794-IE8 module can be installed on a 1794-TB2, 1794-TB3S, 1794-TB3ST, 1794-TB3T, or a 1794-TB3 terminal base unit. It also comes with a power and status indicator and has an open-style enclosure. This module has a voltage specification of 24 Volts DC nominal with supply voltage range of 10.5 to 31.2 VDC including 5% AC ripple.

This module is compatible for analog current signal range such as 0-20mA and 4-20 mA and voltage signal range of +/-10VDC and 0-10VDC inputs. It has a voltage resolution of 2.56 mV/cnt (unipolar) and 5.13 mV/cnt (bipolar) and current resolution of 5.13 µA/cnt. This module has a maximum voltage overload of 30 Volts continuous and a maximum current overload of 32 mA continuous, but there is only one channel for each.

The maximum power dissipation of the 1794-IE8 module is 3 W and the thermal dissipation is 10.2 BTU/hour, both at 31.2 Volts DC. It has an operating vibration of 5 g at 10 to 500 Hertz. Its operating shock is 30 g, while its non-operating shock is 50 g. The operating temperature range of this module is -20 to 55 degrees Celsius while its storage temperature range is -40 to 85 degrees Celsius. The 1794-IE8 module has a current input and voltage input accuracies of 0.20% full scale at 25 degrees Celsius for both, although the voltage input includes the gain, off-set, repeatability, and nonlinearity error terms. The step response to 63% is 9.4 milliseconds for the voltage terminal and 18.2 milliseconds for the current terminal. It has an absolute accuracy of 0.2% full scale at 25 degrees Celsius and accuracy drift with a temperature of 0.00428% full scale per degree Celsius for the voltage terminal and 0.00407% full scale per degree Celsius for the current terminal.