24V dc FLEX I/O RTD Input Module 13
Publication 1794Ć5.22 - May 1999
Specifications - 1794ĆIR8 RTD Input Module
Number of Inputs
8 Channels
Module Location
Cat. No. 1794ĆTB3, ĆTB3S, ĆTB3T, and ĆTB3TS
Terminal Base Units
Signal Input Range
1 to 433 ohms
Sensors Supported
Resistance:
100 ohm Pt
α
= 0.00385 Euro (-200 to +870
o
C)
100 ohm Pt
α
= 0.003916 U.S. (-200 to +630
o
C)
200 ohm Pt
α
= 0.00385 Euro (-200 to +630
o
C)
500 ohm Pt
α
= 0.00385 Euro (-200 to +630
o
C)
100 ohm Nickel
α
= 0.00618 (-60 to +250
o
C)
120 ohm Nickel
α
= 0.00672 (-60 to +250
o
C)
200 ohm Nickel
α
= 0.00618 (-60 to +250
o
C)
500 ohm Nickel
α
= 0.00618 (-60 to +250
o
C)
10 ohm Copper
α
= 0.00427 (-200 to +260
o
C)
Resolution
16 bits across 435 ohms
Data Format
16Ćbit 2's complement or offset binary
Normal Mode Noise Rejection
60db @ 60Hz for A/D filter cutoff @ 10Hz
Accuracy without calibration (at low
humidity)
Normal mode:
0.05% Full Scale (maximum)
Enhanced mode: 0.01% Full Scale (typical)
Common Mode Rejection
-120db @ 60Hz; -100db @ 50Hz with A/D filter
cutoff @ 10Hz
Common Mode Voltage
0V between channels (common return)
System Throughput
Normal mode:
Enhanced mode:
Programmable from 28ms/channel to
325ms/channel
325ms (1 channel scanned)
2.6s (8 channels scanned)
Programmable from 56ms/channel to
650ms/channel
650ms (1 channel scanned)
2.925s (8 channels scanned)
Settling Time to 100% of final value Available at system throughput rate
Open RTD Detection
Out of range reading (upscale)
Open Wire Detection Time
Available at system throughput rate
Overvoltage Capability
35V dc, 25V ac continuous @ 25
o
C
250V peak transient
Channel Bandwidth
dc to 2.62Hz (-3db)
Specifications continued on next page.
