The Allen-Bradley 1734-IB8 is a POINT I/O 8-channel digital DC sinking (NPN) input module designed for 24V DC industrial control signals. It accepts on-state voltages from 10-28.8V DC with a nominal input current of 4 mA at 24V DC. The module provides 3.6 kΩ input impedance, 0.5 ms hardware input filter with 0-63 ms user-selectable software filter for noise rejection. With 50V DC continuous field-to-system isolation (tested at 2500V DC for 60 seconds), the module ensures reliable signal acquisition in noisy industrial environments. Applications include proximity sensor monitoring, limit switch detection, push button and selector switch inputs, and general discrete signal acquisition in distributed automation systems using EtherNet/IP, ControlNet, DeviceNet, or PROFIBUS communication adapters with POINT I/O architecture.
**Q: What is the difference between sinking and sourcing inputs on the 1734-IB8?**
A: The 1734-IB8 is a sinking (NPN) input module. It requires sourcing-type field devices (PNP sensors) that supply positive voltage to the input terminals. For sourcing inputs, use the 1734-IV8 module.
**Q: Does the 1734-IB8 work with AC input signals?**
A: No, the 1734-IB8 is designed for 24V DC signals only. For AC inputs, use the 1734-IA4 (120V AC) module.
**Q: Can I adjust the input filter time for noisy environments?**
A: Yes, the module has a 0.5 ms hardware filter plus a user-selectable software filter from 0 to 63 ms configurable through the PLC programming software.
**Q: Does the module support hot-swapping?**
A: Yes, the 1734-IB8 supports RIUP (Removal and Insertion Under Power), allowing replacement without system shutdown.
