Rockwell Automation 1771-IXE/D Thermocouple/Millivolt Input Module User Manual - Manual (Page 37)

Chapter
5
Publication 1771Ć6.5.130 Ć May 1999
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
(Table 5.A). The processor user program initiates the request to
transfer data from the input module to the processor.
During normal operation the module transfers up to 12 words to the
processor’s data table file. The words contain module status and
input data from each channel. When a block transfer length of zero
(0) is programmed, the 1771–IXE/D will respond with the Series A
default value of 12.
Table 5.A
BTR Word Assignments for Thermocouple/Millivolt Input
Module (1771-IXE/D)
Decimal Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Octal Bit 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
1 Input polarity 1 Status bits
2 Inputs over range 1 Inputs under range 1
3 Inputs > high alarm 1 Inputs < low alarms 1
4 Channel 1 input
5 Channel 2 input
6 Channel 3 input
: :
11 Channel 8 input
12 Cold Junction Temperature in o C
13 Auto-calibration Status Word
1 = one bit per input channel
NOTE: Channel input and calibration words 4-12 are expressed as follows:
o F or o C XXXX BCD
millivolt XX.XX BCD or binary
Cold Junction Temperature XXXX BCD or binary ( o C only)
Chapter Objectives
Reading Data from the
Module