Default configuration – Rockwell Automation 1771-IXHR INSTL INSTR HI RES TC/MV INPUT User Manual
Page 8

High Resolution Thermocouple/Millivolt Input Module
8
Publication 1771-5.66 – October 1998
Use the following table to read data from your input module.
Dec. Bits
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00
De
o
Octal Bits
17
16
15
14
13
12
11
10
07
06
05
04
03
02
01
00
Description
Word 1
Not used
EE
DCB
HCJ
LCJ
RTS OR
PU
Diagnostics
EEPROM status bit – (EE) calibration values could not be read.
High cold junction temperature bit - (HCJ) set when
the cold junction temperature exceeds 60.0
o
C or 140.0
o
F.
Low cold junction temperature bit - (LCJ) set when the
cold junction temperature is less than 0.0
o
C or 32.0
o
F.
Real time sample fault bit – (RTS) 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.
Power up bit – (PU) set to indicate
that the module is waiting for its first
write block transfer.
Out of range bit – (OR) set if one or
more channel inputs are above or below
the range for which you configured the
module.
Dynamic clamp bit - (DCB) 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
Octal Bits
17
16
15
14
13
12
11
10
07
06
05
04
03
02
01
00
Description
2
Inputs overrange
Inputs underrange
Inputs overrange and underrange for
c annel 1-8
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.
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.
channels 1-8
3
Inputs > high alarms
Inputs < low alarms
High and low alarms for
c annel 1-8
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.
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.
channels 1-8
4, 5, 6, 7, 8,
9, 10, 11
Input for channels 1-8 respectively in 0.1
o
C or 0.1
o
F resolution for temperature and 10
µ
V
or 1
µ
V resolution for millivolts.
Input for channels 1-8
12
Cold junction temperature is provided in 0.1
o
C or 0.1
o
F resolution. The filter time constant
(Tau) for this value is fixed at 6.4 seconds.
Cold Junction Temperature
in
_C or _F
13
Uncalibrated channel bits
CF
EE
Not used
S
G
O
Auto-calibration word
EEPROM fault bit
Save to EEPROM bit
Offset calibration complete bit
Calibration fault bit
Gain calibration complete bit
Default Configuration
If a write block of five words with all zeroes is sent to the module,
default selections will be:
•
millivolt input
•
zoom center = 0mV
•
temperature reported in degrees Celsius
•
real time sampling (RTS) inhibited
•
no filtering
•
no auto-calibration