Module status and input data, Chapter – Rockwell Automation 1771-IR Series D RTD Input Module User Manual User Manual
Page 35
Chapter
5
Publication 1771Ć6.5.129 - March 2000
Module Status and Input Data
In this chapter you will read about:
•
reading data from your module
•
input module read block format
Block transfer read programming moves status and data from the
input module to the processor’s data table in one I/O scan. The
processor user program initiates the request to transfer data from the
input module to the processor.
During normal operation, the read block transfer for this module
moves up to 8 words from the RTD module in one program scan.
The words contain module status and input data from each channel.
When a block transfer length of 0 is programmed, the
1771–IR/D will respond with the Series A default of 8 words.
The user program initiates the request to transfer data from the RTD
module to the processor.
Figure5.1
BTR Word Assignments for RTD Input Module
(1771-IR/D)
Decimal Bit
15
14
13 12 11 10 09 08
07
06
05 04 03 02 01 00
Octal Bit
17
16
15 14 13 12 11 10
07
06
05 04 03 02 01 00
1
0
RTS
Timeout
Channel Overrange
EEPROM
calibration
values not
readable
Power-
up
Channel Underrange
2
Not used
Channel Polarity
Not used
Channel Overflow
3
Channel 1 Data
4
Channel 2 Data
5
Channel 3 Data
6
Channel 4 Data
7
Channel 5 Data
8
Channel 6 Data
9
Auto-calibration Status Word
Chapter Objectives
Reading Data from the
RTD Module