A - specifications, Specifications, Appendix – Rockwell Automation 1794-IT8,D17946.5.7 Thermocouple/Millivolt Input Module User Manual
Page 55
Appendix
A
Publication 1794-6.5.7 – March 1997
Template revised June 23, 1995
Specifications
Specifications
1
– 1794-IT8 Thermocouple/mV Input Module
Number of Inputs
8 Channels
Module Location
Cat. No. 1794-TB2, -TB3 and -TB3T Terminal Base Units
2
Nominal Input Voltage Ranges
+76.5mV
Supported Thermocouple Types
Type B: 300 to 1800
o
C
(572 to 3272
o
F)
Type C: 0 to 2315
o
C
(32 to 4199
o
F)
Type E: –230 to 1000
o
C
(–382 to 1832
o
F)
Type J: –195 to 1200
o
C
(–319 to 2192
o
F)
Type K: –230 to 1372
o
C
(–382 to 2502
o
F)
Type N: –270 to 1300
o
C
(–450 to 2372
o
F)
Type R: –50 to 1768
o
C
(–58 to 3214
o
F)
Type S: –50 to 1768
o
C
(–58 to 3214
o
F)
Type T: –195 to 400
o
C
(–319 to 752
o
F)
Type L: –175 to 800
o
C
(–283 to 1472
o
F)
Resolution
16 bits (2.384 microvolts typical)
Accuracy with fixed digital filter
(at 24
o
C (+0.5
o
C))
0.025% Full Scale Range +0.5
o
C
Accuracy without fixed digital filter
(at 24
o
C (+0.5
o
C))
0.05% Full Scale Range +0.5
o
C
Data Format
16-bit 2’s complement or offset binary (unipolar)
Normal Mode Noise Rejection
–60db @ 60Hz
Common Mode Rejection
–115db @ 60Hz; –100db @ 50Hz
Common Mode Input Range
+10V
Channel to Channel Isolation
+10V
System Throughput
325ms (1 channel scanned), programmable to 28ms
2.6s (8 channels scanned), programmable to 224ms
Settling Time to 100% of final value
Available at system throughput rate
Open Circuit Detection
Out of range reading (upscale)
Open Thermocouple Detection Time
Available at system throughput rate
Overvoltage Capability
35V dc, 25V ac continuous @ 25
o
C
250V peak transient
Channel Bandwidth
0 to 2.62Hz (–3db) default
RFI Immunity
Error of less than 1% of range at 10V/M
27 to 1000MHz
Input Offset Drift with Temperature
+6 microvolts/
o
C maximum
Gain Drift with Temperature
10ppm/
o
C maximum
Overall Drift with Temperature
50ppm/
o
C of span (maximum)
Cold Junction Compensation Range
0 to 70
o
C
Cold Junction Compensator
A-B Part Number 969424–01
Indicators
1 red/green power status indicator
Flexbus Current
20mA
Power Dissipation
3W maximum @ 31.2V dc
Specifications continued on next page.