User Manual
Module Status and Input Data
Chapter 6
62
The complete bit/word description for the block transfer read from the module
is defined in Table 6.B.
Table 6.B
Bit/Word
Description for the 1771-IXHR Input Module
Word Bit Definition
Word 1 Bit 00 Power-up bit is set to indicate that the module is waiting for its first
write block transfer
Bit 01 Out of range bit is set if one or more channel inputs are above or
below the range for which you configured the module
Bit 02 Real time sample time-out bit is set when the module updates an
input buffer with new data before the processor has read the previous
data. Monitor this bit only if you select real time sampling.
Bit 03 Not used
Bit 04 Low cold junction temperature bit is set when the cold junction
temperature is less than 0.0
o
C or 32.0
o
F.
Bit 05 High cold junction temperature bit is set when the cold junction
temperature exceeds 60.0
o
C or 140.0
o
F.
Bit 06 Dynamic clamp bit. Prevents rapid changes in data due to data
corruption over the opto-isolation barrier as a result of ESD, radiation
bursts, etc.
0 = feature active
1 = feature inhibited
Bit 07 EEPROM calibration values could not be read.
Bits 08-15 Not used
Word 2 Bits 00-07 Underrange bit for each channel is set to indicate an input is out of
range: bit 00 for channel 1 thru bit 07 for channel 8.
Bits 08-15 Overrange bit for each channel is set to indicate an input is out of
range: bit 08 for channel 1 thru bit 15 for channel 8. Also set for open
channel detection.
Word 3 Bits 00-07 Low alarm bit for each channel is set to indicate the input is less than
the low limit value you entered in the corresponding low alarm word
(BTW word 4, 6, 8, 10, 12, 14, 16, or 18): bit 00 for channel 1 thru bit
07 for channel 8.
Bits 08-15 High alarm bit for each channel is set to indicate the input has
exceeded the high limit value you entered in the corresponding high
alarm word (BTW word 5, 7, 9, 11, 13, 15, 17, or 19): bit 08 for
channel 1 thru bit 15 for channel 8.
Words 4-11 Input for channel 1 through 8 respectively in 0.1
o
C or 0.1
o
F resolution
for temperature and 10
µV or 1µV resolution for millivolts.
Word 12 Cold junction temperature in 0.1
o
C or 0.1
o
F.
Bit/Word Descriptions