AB 1746-NT4 , SLC 500 Thermocouple/MV Analog Input Module , 16 Bits
In, 14 Bits Out
Technical Specifications for 1746-NT4
Manufacturer | Rockwell Automation |
Brand | AB |
Part Number/Catalog No. | 1746-NT4 |
Series | SLC 500 |
Inputs | 4 |
Module Type | Thermocouple/mV Analog Input Module |
Backplane Current (5 Volts) | 60 milliamps |
No. of Inputs | Four (4) |
Backplane Current (24 Volts) | 55 milliamps |
Compatible Thermocouple Sensors | J, K, T, E, S, R, B and N |
Update Time | 26 milliseconds-1.2 seconds |
Compatible miliVolt signal | +/- 50 mV and +/- 100 mV |
Resolution | 16 bits in, 14 bits out |
Backplane Current | 0.06 mA @ 5VDC; 0.04 mA @ 24VDC |
Step Response | 60 milliseconds in, 2.5 milliseconds out |
Backplane Power Consumption | 0.8W maximum (0.3W @ 5V dc, 0.5W @ 24V dc) |
Channels | 4 backplane isolated |
Open Circuit Detection | Zero; Upscale; Downscale |
UPC | 10612598172693 |
I/O Chassis location | Any slot except Slot 0 |
UPC | 10662468165911 |
Operating Temperature | 0 to 60 degrees Celsius |
Storage Temperature | -40 to 85 degrees Celsius |
A/D Conversion method | Sigma-delta modulation |
About 1746-NT4
The Allen Bradley 1746-NT4 is a Thermocouple/mV Input Module for an
SLC 500 system. It provides all SLC 500 processors with a digitally
converted thermocouple or millivolt (mV) analog data, received and
stored in its image table. It does not require any external power
supply as it receives 5 Volts DC and 24 Volts DC power from the SLC
500 power supply through its backplane. It has two cold-junction
compensation (CJC) sensors instead of offset voltages to retain
thermocouple input signal accuracy. Block transfers are required by
this module in a remote I/O configuration. It interfaces to
thermocouple types J, K, T, E, R, S, B, and N, and accepts direct
+/-50 mV and +/-100 mV analog input signals. The 1746-NT4 module
auto calibrates at power-up and whenever a channel is enabled. It
has 5 green LED status indicators, one for module status and one
for each of the four channels.
The 1746-NT4 module has 4 backplane isolated input channels. It has
a backplane current consumption of 60 mA at 5 Volts DC and 40 mA at
24 Volts DC. It has a backplane power consumption of 0.3 Watts at 5
Volts DC and 0.5 Watts at 2 Volts DC, a 16-bit converter
resolution, and a 12 to 300 millisecond Step response at 95%. It
has a bandwidth of 2.62 - 65.5 Hertz and a 26 millisecond - 1.2
second update period and uses sigma-delta modulation for A/D
conversion. It can be installed in any slot except slot 0 of the
SLC 500 chassis. It uses two wires per terminal with a maximum wire
size of 2.5 millimeters (14 AWG) and 25 ohms maximum cable
impedance. For Thermocouple inputs, use shielded twisted
thermocouple extension wire; for mV inputs, Belden 8761 or
equivalent wire must be used.
The 1746-NT4 is an AB module used with Thermocouple sensors and mV
signals. This module belongs to analog input module category which
belongs to the SLC 500 product family.
It features Eight (8) Thermocouple inputs with each channel
supporting a wide variety of Thermocouple types such as J, K, T, E,
S, R, B and N. Compatible mV signals include +/- 50 mV and +/- 100
mV. Each input channel is built with broken sensor detection may
indicate a shorted or open circuit. There are configurable settings
when an open circuit is detected such as Zero, Upscale and
Downscale. When Zero is configured, the module’s reading is forced
to Zero (0). When set to Downscale, the module’s reading is forced
to the lowest reading while Upscale forces the reading to the
maximum reading. These settings are helpful as it may be used to
quickly diagnose the state of each channel aside from the visible
LED indicators for each channel. The fault reaction settings must
be based on the fail-safe operation of the process. These settings
are configured with the use of RSLogix 500 Programming software.
Individual channel filters may also be set to fine tune the
module’s behavior to input. Channel filters are set to minimize the
effect of electrical noise and AC lines that may cause fluctuations
and erratic readings. Selectable filter frequencies are 250 Hz
which offers minimize noise filtering, 60 Hz, 50 Hz and 10 Hz noise
filtering. If a Cold Junction Compensation (CJC) input is selected,
input filter is ignored.