Rockwell Automation 1771-IXHR , D17716.5.80 HIGH RESOL.THERMOCOUPLE - Manual (Page 9)

Chapter 2
2
Chapter
2Ć1
Overview of the High Resolution
Thermocouple/Millivolt Input Module
This chapter gives you information on:
features of the input module
how an input module communicates with programmable controllers
The High Resolution Thermocouple/Millivolt input module is an intelligent
block transfer module that interfaces analog input signals with any
Allen–Bradley programmable controllers that have block transfer capability.
Note: Use with PLC–2 family programmable controllers is not recommended.
The 1771–IXHR module is only available with 2’s complementary binary as its
only data type. The PLC–2 family does not use 2’s complementary binary.
Block transfer programming moves input data words from the module’s
memory to a designated area in the processor data table in a single scan. It also
moves configuration words from the processor data table to module memory.
The input module is a single slot module which does not require an external
power supply. After scanning the analog inputs, the input data is converted to a
specified data type in a digital format to be transferred to the processor’s data
table on request. The block transfer mode is disabled until this input scan is
complete. Consequently, the minimum interval between block transfer reads is
the same as the total input update time for each analog input module (25ms).
The 1771–IXHR module senses up to 8 differential analog inputs and converts
them to values compatible with Allen–Bradley programmable controllers.
This module’s features include:
8 input channels configurable for thermocouple input ranges or millivolt
input ranges: Types B, E, J, K, T, R and S thermocouples and +100 millivolts
two types of inputs allowed: 4 of one input type and 4 of another
cold junction compensation
scaling to selected temperature range in
o C or o F
temperature resolution of 0.1 o C or 0.1 o F, millivolt resolution to 1 microvolt
user selectable high and low temperature alarms
all features selectable through programming
Chapter Objectives
Module Description
Features of the Input Module