PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1794-IT8 is an analog input module for the FLEX I/O system. It provides eight input channels for thermocouple and millivolt signals. Supported thermocouple types include J, K, E, R, N, S, B, C, T, and L. The unit also accepts millivolt inputs within a range of -76.5 mV to +76.5 mV. Analog-to-digital conversion provides 16-bit resolution with typical steps of 2.384 microvolts.
This module operates on terminal base units including 1794-TB2, 1794-TB3, and 1794-TB3T. Mounting requires setting the terminal base keyswitch to Position 3. Two cold junction compensators mount directly on designated terminal base locations. Communication with programmable controllers occurs through standard block transfer operations. The front panel features one red and green status indicator. An inserted front label provides eight fields for channel identification.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
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| Product Line | Flex I/O 1794 |
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| UPC | 612598137831 |
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| Weight | 0.56 lbs (0.26 kg) |
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| Power Dissipation | 3W maximum @ 31.2V |
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| Resolution | 16 bits (2.384 microvolts typical) |
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| No. of Inputs | 8 |
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| Sensors supported | J, K, E, R, N, S, B, C, T and L |
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| millivolt signal | +/- 76. 5mV |
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| Data Format | 16-bit 2’s complement or offset binary (unipolar) |
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| Indicator | 1 red/green power status indicator |
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| CJC unit | A-B Part Number 969424–0 |
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| Module Location | 1794-TB2, -TB3 and -TB3T Terminal Base Units |
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| Keyswitch Position | 3 |
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| Inputs | 8 Channels |
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| Nominal Input Ranges | -76.5 to 76.5 mV |
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| Isolation Voltage | 850 Volts DC |
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| Normal Mode Noise Rejection | -60db at 60 Hertz |
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| Channel Bandwidth | 0 to 2.62 Hertz |
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| Normal Mode System Throughput | 325 milliseconds |
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| Flexbus Current | 20 mA |
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| Thermal Dissipation | 10.2 BTU/hour at 31.2 Volts DC maximum |
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TECHNICAL INFORMATION
Features
- Eight input channels for direct thermocouple and millivolt sensor connections.
- Direct linearization for thermocouple sensor types J, K, E, R, N, S, B, C, T, and L.
- Analog-to-digital conversion offering 16-bit resolution with 2.384 microvolt typical steps.
- Includes two cold junction compensation sensors for terminal base mounting.
- Field-to-backplane isolation rated at 850 Volts DC.
- Supports block transfer programming for configuration and data exchange.
TECHNICAL INFORMATION
Applications
- Temperature monitoring across thermocouple types B, C, E, J, K, L, N, R, S, and T.
- Direct acquisition of low-level signals from transducers producing up to +/-76.5 mV.
- Temperature measurement using grounded or ungrounded thermocouple sensor assemblies.
TECHNICAL INFORMATION
Connections / Interfaces
- Eight input channels for wiring grounded or ungrounded thermocouple sensors.
- Two dedicated mounting points on the terminal base for cold junction compensators.
- Internal Flexbus connection consuming 20 mA backplane current.
TECHNICAL INFORMATION
Installation Guidelines
- Rotate the terminal base keyswitch to Position 3 before mounting the module.
- Install the unit onto a 1794-TB2, 1794-TB3, or 1794-TB3T terminal base.
- Mount the two cold junction compensators in the specified terminal base positions.
- Press the module firmly into the terminal base until locked securely.
TECHNICAL INFORMATION
Configuration Guidelines
- Configure channel parameters and scaling using controller block transfer programming.
- Select between 16-bit two's complement and unipolar offset binary data formats.
- Ensure input configuration matches the installed thermocouple type or millivolt source.
TECHNICAL INFORMATION
Compatibility
- Compatible with all Allen-Bradley FLEX I/O communication adapters.
- Mounts on 1794-TB2, 1794-TB3, and 1794-TB3T terminal base units.
- Accepts grounded and ungrounded thermocouple sensor inputs.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSCompatible with all Allen-Bradley FLEX I/O communication adapters. Mounts on 1794-TB2, 1794-TB3, and 1794-TB3T terminal base units. Accepts grounded and ungrounded thermocouple sensor inputs.
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
Which terminal base units work with the 1794-IT8?
The 1794-IT8 mounts on 1794-TB2, 1794-TB3, and 1794-TB3T terminal base units.
What keyswitch position is required for installation?
Rotate the terminal base mechanical keyswitch to Position 3 before inserting the module.
Which thermocouple sensor types can be connected?
The module supports thermocouple types B, C, E, J, K, L, N, R, S, and T.
What is the market reference price for the 1794-IT8?
Observed market reference pricing is approximately $1,190 for refurbished units. This figure is an indicative market reference only and is not a final quotation.
