Allen-Bradley 1794-IRT8 - Input Module (1794-IRT8)

Publication 1794-6.5.12 - November 1997
How Communication Takes Place and I/O Image Table Mapping with the DeviceNet Adapter 5-5
Bit/Word Descriptions for the Thermocouple/RTD/mV Input Module
(1794-IRT8)
Word
Dec. Bits
(Octal Bits)
Description
Read Word 1 00-15 (00-17) Channel 0 Input data
Read Word 2 00-15 (00-17) Channel 1 Input data
Read Word 3 00-15 (00-17) Channel 2 Input data
Read Word 4 00-15 (00-17) Channel 3 Input data
Read Word 5 00-15 (00-17) Channel 4 Input data
Read Word 6 00-15 (00-17) Channel 5 Input data
Read Word 7 00-15 (00-17) Channel 6 Input data
Read Word 8 00-15 (00-17) Channel 7 Input data
Read Word 9 00-07 Underrange bits – these bits are set if the input signal is below the input channel’s minimum range.
Bit 00 corresponds to channel 0, bit 01 corresponds to channel 1, etc.
08-15 (10-17) Overrange bits – these bits are set if 1), the input signal is above the input channel’s maximum
range, or 2), an open detector is detected. Bit 08 (10) corresponds to channel 0, bit 09 (11)
corresponds to channel 1, etc.
Read Word 10 00-03 Diagnostic bits – represent module configuration and/or hardware errors.
Bit03020100
0000Reserved for factory use
0010Improper module configuration
0001 and 0011 thru 1111 Reserved for factory use
04 Not used.
05-06 Cold junction compensation alarm bits – These bits are set (1) when the corresponding cold
junction compensator lead is broken, unattached or shorted. Bit 05 corresponds to CJC1, and bit 06
to CJC2.
07 Not used
08-15 (10-17) Fault alarm bits – An alarm bit is set (1) when an individual input lead opens (broken,
disconnected). If the alarm is enabled, the channel reads maximum value. Bit 08 (10) corresponds to
input channel 0, bit 09 (11) to channel 1, etc.
Read Word 11 00-07 Extended data table command response data bits – These bits echo the EDT command data
written to the module during calibration.
08-14 (10-16) Extended data table command response bits – These bits echo the EDT command written to the
module during calibration.
15 (17) Reserved for factory use