Specifications

Publication 1747-SG001E-EN-E - February 2013
Select SLC 500 I/O Modules 27
RTD Input Modules
The RTD modules interface with platinum, nickel, copper, and nickel-iron RTDs, and
with variable resistance devices such as potentiometers (0 to 3000Ù maximum). The
module provides on-board RTD temperature scaling in degrees Celsius and degrees
Fahrenheit or resistance scaling in ohms.
DC Millivolt Input Ranges for 1746-NT4, 1746-NT8, and 1746-INT4 Modules
Input Type Range Accuracy @ 25 °C (77 °F)
±50 mV -50 mV dc…+50 mV DC 50 μV
±100 mV -100 mV DC…+100 mV DC 50 μV
TIP
Block transfers are required in a remote I/O configuration,
using a 1747-ASB with a PLC.
RTD/Resistance Input Modules
Attribute 1746-NR4 1746-NR8
Backplane current (mA) @ 5 V 50 mA 100 mA
Backplane current (mA) @ 24V 50 mA 55 mA
Number of inputs 4 8
Input type 100 Ω Platinum (385)
200 Ω Platinum (385)
500 Ω Platinum (385)
1000 Ω Platinum (385)
100 Ω Platinum (3916)
200 Ω Platinum (3916)
500 Ω Platinum (3916)
1000 Ω Platinum (3916)
10 Ω Copper (426)
120 Ω Nickel (618)
120 Ω Nickel (672)
604 Ω Nickel-Iron (518)
150 Ω Resistance Input
500 Ω Resistance Input
1000 Ω Resistance Input
3000 Ω Resistance Input
Temperature scale (selectable) 1 °C or 1 °F and 0.1 °C and 0.1 °F
Resistance scale (selectable) 1 or 0.1 Ω for all resistance ranges; or 0.1 Ω or 0.01 Ω for 150 Ω potentiometer
Filter frequency (selectable filter) 10 Hz
50 Hz
60 Hz
250 Hz
28 Hz
50/60 Hz
800 Hz
6400 Hz
RTD excitation current
(Two current values are user-selectable)
0.5 mA
(1)
2.0 mA
(2)
0.25 mA
(1)
1.0 mA
(2)
Open-circuit or short-circuit detection Zero, upscale or downscale
Maximum cable impedance 25 Ω maximum per 308.4 m (1000 ft)
Data formats Raw/Proportional, Engineering Units, Engineering Units x 10, Scaled-for-PID
Calibration Autocalibration at powerup and when a channel
is enabled
Autocalibration at powerup and user-enabled periodic
calibration