PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1746-NR8 SLC 500 Analog Input Module provides eight channels of RTD and resistance acquisition. It installs into a single chassis slot across SLC 500 fixed and modular hardware platforms. The unit derives operating power directly from the backplane without external power supplies. Power consumption reaches 1.82 W maximum, drawing 100 mA at 5 VDC and 55 mA at 24 VDC.
The hardware performs analog-to-digital conversions through sigma-delta modulation. Automatic calibration executes at power-up and can run at five-minute intervals. Supported sensor types include platinum, copper, nickel, and nickel-iron resistance detectors. Direct resistance measurements range across 0 to 150, 500, 1000, and 300 Ohms. Front-panel LED indicators report channel operation and diagnostic status.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
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| A/D Conversion method | Sigma-delta modulation |
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| Backplane Current | 100 mA @ 5VDC; 55 mA @ 24VDC |
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| Backplane Current (24 Volts) | 55 milliamps |
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| Backplane Current (5 Volts) | 100 milliamps |
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| Backplane Power Consumption | 1.82W maximum (0.5W at 5V dc, 1.32W at 24V dc) |
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| Category | PLCs |
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| Compatible RTD Sensors | Platinum (385) 100, 200, 500 and 1000; Platinum (3816) 100, 200, 500 and 1000; Copper (426) 10, Nickel (618) 120, Nickel (672) 120, and Nickel Iron (518) 604. |
|---|
| Compatible Resistance input range | 0 - 150 Ohms, 0 to 500 Ohms, 0 to 1000 Ohms and 0 to 300 Ohms |
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| I/O Chassis location | Any slot except Slot 0 |
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| Inputs | 8 |
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| Module Type | RTD/Resistance Analog Input Module |
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| No. if Inputs | Eight (8) |
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| Operating Temperature | 0 to 60 degrees Celsius |
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| Operating Temperature Range | 32 to 140 degrees Fahrenheit |
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| Resolution | .01 Deg. Celcius |
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| Step Response | 60 milliseconds in, 2.5 milliseconds out |
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| Storage Temperature | -40 to 85 degrees Celsius |
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| UNSPSC | 32151705 |
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| UPC | 611320271720 |
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| Update Time | 6 milliseconds to 2 seconds |
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| Weight | 0.69 lbs (0.31 kg) |
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TECHNICAL INFORMATION
Features
- Accepts eight RTD or direct resistance input channels.
- Employs sigma-delta analog-to-digital conversion.
- Offers programmable input filters and a low-pass digital filter.
- Features power-up autocalibration with programmable five-minute cycles.
- Operates on backplane power without requiring an external supply.
TECHNICAL INFORMATION
Applications
- Temperature monitoring using RTD sensor elements.
- Mechanical displacement and travel measurement via resistance variation.
TECHNICAL INFORMATION
Connections / Interfaces
- Compatible with the Allen-Bradley 1746-RT-35 removable terminal block.
- Removable terminal block terminals accept single wire connections only.
- Supports 2-wire, 3-wire, and 4-wire RTD sensor wiring configurations.
- Recommended wiring for 2-wire RTDs is Belden 9501 shielded cable.
- Recommended wiring for 3-wire and 4-wire RTDs is Belden 9533 or 83503.
TECHNICAL INFORMATION
Installation Guidelines
- Install the module into any chassis slot except Slot 0.
- Avoid long cable runs on 2-wire RTD circuits to preserve accuracy.
- Use heavier gauge wire such as AWG 16 to reduce wire resistance.
- Maintain continuous channel-to-channel isolation at 5 VDC.
TECHNICAL INFORMATION
Configuration Guidelines
- Configure digital filtering parameters to match process update needs.
- Update times range from 6 milliseconds to 2 seconds depending on settings.
- Set autocalibration cycles to run every 5 minutes during operation.
TECHNICAL INFORMATION
Compatibility
- SLC 500 fixed chassis hardware.
- SLC 500 modular chassis hardware.
- Allen-Bradley 1746-RT-35 removable terminal block.
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSSLC 500 fixed chassis hardware. SLC 500 modular chassis hardware. Allen-Bradley 1746-RT-35 removable terminal block.
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
What chassis slots accommodate the 1746-NR8 module?
The module installs into any SLC 500 chassis slot except Slot 0.
Which RTD sensor types can connect to the 1746-NR8?
It accepts Platinum, Copper, Nickel, and Nickel-Iron RTDs. Direct resistance inputs are also supported.
Does the 1746-NR8 require an external power supply?
No external supply is needed. Backplane power provides 100 mA at 5 VDC and 55 mA at 24 VDC.
What terminal block connects field wiring to the 1746-NR8?
Field wiring connects using an Allen-Bradley 1746-RT-35 removable terminal block.
