GE FANUC IC670ALG620 Analog Module

GE FANUC IC670ALG620 Analog Module

What is IC670ALG620?

RTD 4 Channel Isolated 3 or 4 Wire Analog Input Module

The RTD Analog Input Module (IC670ALG620) accepts inputs from 4 independent 3-wireand/or 4-wire platinum, nickel, nickel/iron, or copper RTDs.

IC670ALG620-KD

IC670ALG620-HC

Module features include:

Selectable resistance measurements in tenths of ohms, tenths of degrees Fahrenheit, or

tenths of degrees Celsius

Individual channel configuration

Selectable resistance ranges: 0 – 500 ohms and 0 – 3000 ohms

Selectable RTD input as resistance or temperature (Celsius or Fahrenheit)

Reports high/low, underrange/overrange, open wire and input short alarms.

Uses optional discrete inputs and outputs for status and control.

Two data acquisition rates based on 50 Hz and 60 Hz line frequencies

Configurable channel activation

Module Operation

The RTD Input Module accepts four inputs from three-wire or four-wire RTDs and convertsthe input level to a digital value. Input spans support a variety of RTD types, as listed in theModule Specifications section.

The analog/digital converter reads the voltage generated by each of the four inputs. The A/Dconverter converts the differential measurement into a binary value (15 bits plus sign),which is read by the block’s microprocessor. The microprocessor sets the gain required in theanalog/digital converter for each individual input. The gain is based on the RTD type thathas been configured for that input.

The microprocessor selects the input by means of a solid state, optically-coupled multiplexer.Three measurements are made for each input: Excitation current, RTD resistance includingfield wire drop, and field wire drop. From these three measurements, the module calculatesthe RTD resistance. A DC/DC converter circuit isolates the field side from the logic circuits.