Rockwell Automation 1771-IXHR , D17716.5.80 HIGH RESOL.THERMOCOUPLE - Manual (Page 10)

Overview of the High Resolution
Thermocouple/Millivolt Input Module
Chapter 2
2Ć2
self–diagnostics and status reporting at power–up
detection of open circuit if thermocouple fails
automatic offset and gain calibration for each channel
software calibration of all channels, eliminating potentiometers
programmable filters for each group of 4 inputs
X10 magnification (zoom) for millivolt mode
The processor transfers data to and from the module using BTW (block transfer
write) and BTR (block transfer read) instructions in your ladder diagram
program. These instructions let the processor obtain input values and status
from the module, and let you establish the module’s mode of operation
(Figure 2.1).
1. The processor transfers your configuration data and calibration values to
the module using a block transfer write instruction.
2. External devices generate analog signals that are transmitted to the
module.
Figure 2.1
Communication Between Processor and Module
Memory
User Program
To Output Devices
PC Processor
(PLC-5/40 Shown)
High Resolution
Thermocouple/Millivolt
Input Module
1771-IXHR
BTW
BTR
5
6
2
3
12933-I
1
4
3. The module converts analog signals into binary format, and stores these
values until the processor requests their transfer.
How Analog Modules
Communicate with
Programmable Controllers