1746-IB16 16-Channel 24V DC Sinking Input Module Allen-Bradley

1746-IB16 16-Channel 24V DC Sinking Input Module

Product Introduction

The 1746-IB16 belongs to the Allen‑Bradley SLC 500 family. This digital DC input module features 16 sinking input channels grouped into one common group. Its nominal signal voltage is 24V DC, with an operating range from 10V to 30V DC.

Additionally, this module draws 85mA from the 5V DC backplane. It supports only sinking wiring configurations. Therefore, you can use it with limit switches, proximity sensors, pushbuttons, relay contacts, and contactor auxiliaries.

The 1746-IB16 has a fast and consistent signal delay. Both ON and OFF transitions take just 8ms maximum. This response time suits most high‑speed industrial control applications.

For simplified troubleshooting, each channel includes a status LED indicator. The module also features a removable terminal block (RTB). Consequently, you can replace the module without rewiring the field devices.

Technical Specifications

Here are the complete technical details for the 1746-IB16:

• Inputs: 16 (sinking, one common group)

• Input voltage range: 10–30V DC (nominal 24V DC)

• Nominal input current: 8mA at 24V DC

• Backplane current (5V DC): 85mA

• Backplane current (24V DC): 0mA

• Signal delay (ON): 8ms max

• Signal delay (OFF): 8ms max

• Off‑state max voltage: 5.0V DC

• Off‑state max current: 1mA

• Thermal dissipation per channel: 0.20W

• Total thermal dissipation: 3.6W

• Step response: 100ms in, 2.5ms out

• Isolation voltage: 1500V (input to logic)

This I/O module uses 1746-HT or 1746-HCA connectors. It occupies exactly one slot in any SLC 500 chassis.

Mechanical & Environmental Parameters

The 1746-IB16 measures 5 inches high by 2 inches wide by 6 inches deep (13 cm x 5 cm x 15 cm). It weighs 0.23 kg, and the gross packaged weight is 0.32 kg.

Operating temperature ranges from 32°F to 140°F (0°C to 60°C). Storage temperature spans from -40°F to 185°F (-40°C to 85°C). Relative humidity tolerance is 5–95% non‑condensing.

Moreover, this module has a tested operational shock rating of 30G. It withstands operational vibration of 2.5G at 57–200 Hz. Noise immunity meets NEMA standard ICS 2‑230.

Hazardous Location & Certifications

The 1746-IB16 carries multiple important certifications. It is UL listed, CSA certified, and CE marked. Furthermore, it holds C-UL Class I, Division 2 approval for hazardous environments.

Electro-optical isolation is tested at 1500V between input terminals and control logic. This isolation protects your backplane from field side surges. Always verify local requirements before installing in hazardous areas.

Installation & System Compatibility

You can install the 1746-IB16 in any available SLC 500 chassis slot. The number of modules per system depends on your CPU’s I/O memory capacity.

Local installation places the module in the same chassis as the SLC 500 CPU. Alternatively, you can use it in a distributed I/O chassis. For distributed setups, pair it with a 1746 communication adapter such as Remote I/O (RIO) or Ethernet adapter modules.

First, power down the chassis. Then, slide the 1746-IB16 into the selected slot until the backplane connector seats. Tighten the retention screws. Wire your DC sinking devices to the removable terminal block, then insert the block into the module.

Packaging List

• 1 x Allen‑Bradley 1746-IB16 digital DC sinking input module

• 1 x removable terminal block (RTB)

• 1 x installation instructions

Note: Certificates and warranty documents are not included. The module ships in anti‑static protective packaging.

Shipping method: FedEx, UPS, or DHL (express delivery with full tracking).

Frequently Asked Questions (FAQ)

1. Can the 1746-IB16 accept sourcing inputs?
No, the 1746-IB16 supports sinking inputs only. For sourcing applications, use the 1746-IB32 or other sourcing input modules.

2. What is the maximum off‑state voltage allowed?
The off‑state voltage must stay below 5.0V DC. If the voltage exceeds this value, the input may falsely turn on.

3. How do I know which channel is active?
Each of the 16 channels has a dedicated status LED on the front panel. When the LED is on, the corresponding input is active.

4. Can I replace the module without removing field wiring?
Yes, the removable terminal block allows you to disconnect the wiring. Simply pull the RTB off, replace the 1746-IB16, and reattach the RTB.

5. What is the difference between 1746-IB16 and 1746-IB8?
The 1746-IB16 offers 16 inputs and draws 85mA. The 1746-IB8 has 8 inputs and draws 50mA. Both are sinking type with 8ms signal delay.