Description
Description
The Allen-Bradley 1746-IB8 is a high-performance digital DC input module designed for use within the SLC 500 programmable logic controller system. This module provides eight (8) current-sinking input channels, allowing the PLC to monitor the status of various field devices such as limit switches, pushbuttons, and proximity sensors. It reliably converts 24V DC field signals into logic-level data for processing by the SLC 500 controller.
Features
- Eight (8) isolated current-sinking input channels.
- Nominal operating voltage of 24V DC with an operating range of 10-30V DC.
- Integrated hardware filtering with an 8 ms signal delay to mitigate mechanical contact bounce.
- Robust design offering high noise immunity and resistance to shock up to 30G.
- Backplane power consumption of 50 mA at 5V DC.
- 1500V AC isolation between the backplane and the input circuitry.
Applications
The 1746-IB8 is widely utilized in industrial automation environments for discrete signal monitoring. It is commonly deployed in manufacturing lines, material handling systems, and process control applications where reliable detection of binary field device states is required.
Technical Specifications
| Brand |
Allen-Bradley |
| Product Line |
SLC 500 |
| Module Type |
Digital DC Input Module |
| Number of Inputs |
8 (Current Sinking) |
| Nominal Input Voltage |
24V DC |
| Operating Voltage Range |
10–30V DC |
| Off-State Voltage (Max) |
5.0V DC |
| Off-State Current (Max) |
1 mA |
| Nominal Input Current |
8 mA @ 24V DC |
| Backplane Current (5V DC) |
50 mA |
| Power Dissipation |
1.3 Watts Total |
| Isolation |
1500V AC |
| Operating Temperature |
0 to 60 degC |
Installation Guidelines
- Ensure the PLC chassis is powered down before inserting or removing the module to prevent electrical damage.
- The 1746-IB8 must be installed in an SLC 500 chassis; ensure the module is fully seated and the retaining screws are tightened to provide a secure ground connection.
- Use shielded cabling for input signals to minimize electromagnetic interference (EMI) in high-noise environments.
- Maintain proper ventilation within the enclosure to ensure the ambient temperature remains within the 0 to 60 degC operating range.
- Verify that field devices are correctly wired for a sinking configuration, where the device sources current to the module input.
FAQ
What is the primary function of the 1746-IB8 module?
The 1746-IB8 is a digital input module that detects 24V DC signals from field sensors and switches, converting them into digital signals that the SLC 500 processor can interpret.
Does this module require external power for the inputs?
Yes, the 1746-IB8 requires an external 24V DC power supply to energize the input field devices, as the module itself does not provide power to the sensors.
