Allen-Bradley 1794-IRT8

Technical specifications

Manufacturer

Allen-Bradley

Manufacturer part no.

1794-IRT8

Type

Analog input module

Application

I/O module

Used with

FLEX I/O adapters and terminal bases

Input resolution

14 bits

Supported Thermocouple types

Type B: 300…1800 °C (572…3272 °F), Type E: -270…+1000 °C (-454…+1832 °F), Type J: -210…+1200 °C (-346…+2192 °F), Type K: -270…+1372°C (-454…+2502 °F), Type N: -270…+1300°C (-454…+2372 °F), Type R: -50…+1768°C (-58…+3214 °F), Type S: -50…+1768°C (-58…+3214 °F), Type T: -270…+400°C (-454…+752 °F), Type TXK/XK (L): -200…+800°C (-328…+1472 °F)

Accuracy

0.05% of full range in mV mode with filtering selected, Hardware only = 0.10% of full range in mV mode

Common mode rejection ratio

-80 dB @ 5V peak-to-peak 50…60 Hz

Common mode input range

Series A – ±4V, Series B – ±15V

Open circuit detection type

Series A: RTD and TC modes - Open input – Module defaults to max value, Series B: RTD mode - Open input – Module defaults to max value, Series B: TC mode - Open input – Module defaults to min value

Excitation current

630 µA

Overvoltage capability

Series A: 7V DC continuous @ 25 °C (77 °F), Series B: 15V DC continuous @ 25 °C (77 °F)

Open input detection time

0…3.8 s for Series A, revision D or earlier, Immediate detection (max 2 scans) for Series A, revision E or later, Immediate detection (max 2 scans) for Series B

Cold junction compensation range

0…70 °C for firmware Series A, revision D or earlier -20…+100 °C for firmware Series A, revision E or later -20…+100 °C for firmware Series B

Cold junction compensation

Allen-Bradley Cold Junction Compensation Kit, 1794-CJC

Overall drift with temperature, max

Series A: 150 ppm/°C of span, Series B: 50 ppm/°C of span

Dimensions (HxWxD), approx

46 x 94 x 53 mm (1.8 x 3.7 x 2.1 in.) 94 x 94 x 69 mm (3.7 x 3.7 x 2.7 in.) installed

Temperature, operating

-20…+55 °C (-4…+131 °F)

Technical documents (1)

• Rockwell Automation FLEX I/O selection guide 1794-SG002

Key features

• Non-isolated input module for thermocouple, RTD and mV signals
• Supports thermocouple types B, E, J, K, N, R, S, T and TXK/XK (L)
• Cold junction compensation with the 1794-CJC kit
• Series B overall drift is 50 ppm/°C of span maximum
• Open input detection within 2 scans on Series B

About the Allen-Bradley 1794-IRT8

The 1794-IRT8 is a FLEX I/O 8 point non-isolated input module for thermocouple, RTD and mV signals. Resolution is 14-bit; accuracy in mV mode is 0.05% of full range with filtering selected, or 0.10% with hardware only. It works from -20…+55 °C and measures approximately 46 x 94 x 53 mm, or 94 x 94 x 69 mm installed.

What is the 1794-IRT8 used for?

It reads temperature sensors into a FLEX I/O node. Cold junction compensation uses the 1794-CJC kit, with a range of -20…+100 °C on Series B. On an open input a Series B module reads the max value in RTD mode and the min value in thermocouple mode.

Lifecycle and successor

Active Mature (Rockwell Automation lifecycle status, checked 24 October 2026).

Before you order

What to photograph or confirm so the right unit is quoted.

Read the catalog number 1794-IRT8, the series letter and the firmware revision from the label. Send us a photo of the label and we confirm the match before we quote.