1746-ITV16 Allen Bradley SLC 500 Sourcing Input

1746‑ITV16 Allen Bradley SLC 500 Fast Response Sourcing Input Module

The 1746‑ITV16 from Allen‑Bradley is a high‑speed discrete input module engineered for the SLC 500 controller platform. This module delivers 16 sourcing input channels that accept DC voltage signals from a variety of field devices, including proximity sensors, pushbuttons, and high‑frequency pulse generators. Its fast response characteristic distinguishes it from standard input modules. Specifically, the 1746‑ITV16 achieves a maximum ON‑state signal delay of 0.3 ms and a maximum OFF‑state delay of 0.5 ms, with typical delays as low as 0.1 ms and 0.25 ms respectively at 24V DC operation. Consequently, this module excels in applications requiring rapid switching detection, such as encoder feedback, totalizer counting, and high‑speed conveyor positioning. Moreover, the 1746‑ITV16 employs a source wiring configuration, which means the field device supplies the positive voltage to the input channel. This design simplifies integration with sourcing‑type sensors commonly found in industrial automation. Therefore, the 1746‑ITV16 offers a robust and reliable solution for time‑critical discrete input tasks.

Technical Specifications of the 1746‑ITV16

A thorough understanding of the electrical parameters ensures proper system design and integration. First, the 1746‑ITV16 operates across a wide input voltage range of 10–30V DC, with a nominal value of 24V DC. This broad window accommodates typical power supply fluctuations in industrial environments. Each channel draws a nominal input current of 8 mA at 24V DC, providing adequate drive capability for reliable state sensing. Additionally, the maximum off‑state voltage is specified at 5V DC, and the maximum off‑state current is 1.0 mA (with some references noting 1.5 mA), ensuring a distinct logic‑low condition. The module consumes 0.085 A (85 mA) from the 5V DC backplane supply, placing a modest load on the chassis power source. Furthermore, the 1746‑ITV16 dissipates up to 3.6 W of power, so proper ventilation within the control cabinet is advisable. The module features a single group of 16 inputs without individual channel isolation, which is typical for high‑speed designs that prioritize response time over galvanic separation.

Fast Response and High‑Speed Performance

The primary advantage of the 1746‑ITV16 lies in its exceptional speed. For instance, the ON‑transition signal delay is as low as 0.1 ms under typical conditions, while the OFF‑transition delay reaches just 0.25 ms at 24V DC. These rapid response times enable the module to capture short‑duration pulses and high‑frequency signals with minimal latency. Consequently, the 1746‑ITV16 is ideally suited for applications involving encoders, totalizers, data loggers, and counters. Moreover, when used with high‑frequency signaling devices, the module can track position changes or count events accurately without missing transitions. Additionally, the built‑in filter circuitry and optical coupling provide effective noise reduction, which is critical in electrically noisy environments with motors, drives, or welding equipment. Therefore, the 1746‑ITV16 delivers reliable performance in motion control, packaging machinery, and high‑speed inspection systems where timing precision is paramount.

Installation and Wiring Guidelines

Correct installation maximizes the module’s performance and service life. Begin by ensuring that power to the SLC 500 chassis is completely removed, as the 1746‑ITV16 does not support removal under power (RIUP). Next, insert the module into any available slot of the 1746 chassis, applying firm, even pressure until the retaining clips engage securely. The module connects directly to the backplane for both power and data communication. For wiring, use copper conductors with a gauge of 0.5 – 1.5 mm² (22–16 AWG). Strip approximately 7 mm of insulation and terminate each field device wire to the corresponding input terminal. Pay special attention to the wiring configuration: the 1746‑ITV16 uses source wiring, meaning the field device must supply the positive voltage to the input, while the module’s common terminal connects to the DC supply negative. After completing all connections, verify each termination against the terminal layout diagram. Finally, apply power and check the LED indicators – each channel has a dedicated status light that illuminates when the input is active. These LEDs greatly simplify commissioning and fault‑finding.

Mechanical and Environmental Parameters

The 1746‑ITV16 occupies a single slot in the SLC 500 chassis, conserving valuable rack space for additional modules. Its operating temperature range spans 0°C to 60°C (32–140°F), while storage conditions extend from -40°C to 85°C. Relative humidity tolerance is 5% to 95% non‑condensing, ensuring dependable operation in humid plant environments. The module meets industrial standards for vibration and shock resistance, so it withstands typical machinery oscillations and minor impacts. Additionally, the unit carries an open‑type enclosure rating, which means it must be installed inside a suitable control cabinet to protect against dust, moisture, and accidental contact. Therefore, always follow local electrical codes and panel design best practices when planning your installation.

Packaging List

• 1746‑ITV16 fast response sourcing input module (1 unit)

• Removable terminal block (pre‑installed)

• Slot filler cover

• Installation instructions leaflet

Shipping via FedEx, UPS, or DHL – tracking number provided upon dispatch.

Frequently Asked Questions (FAQ)

1. What is the difference between the 1746‑ITV16 and the 1746‑ITB16?
Both are fast response input modules, but the 1746‑ITV16 uses sourcing wiring (field device supplies +V), while the 1746‑ITB16 uses sinking wiring (field device switches –V). Choose based on your sensor output type.

2. Can the 1746‑ITV16 handle encoder signals directly?
Yes, the 1746‑ITV16 can accept encoder pulse signals up to 2 kHz when used with compatible devices. Its fast 0.3 ms ON‑delay ensures accurate pulse counting and position tracking.

3. Is the 1746‑ITV16 compatible with all SLC 500 processors?
Yes, the 1746‑ITV16 works with all SLC 500 fixed and modular processors. However, for advanced features like discrete input interrupts, an SLC 5/03 or higher processor is recommended.

4. How do I troubleshoot a non‑responsive channel on the 1746‑ITV16?
First, check the corresponding LED – if it is off, verify the field device’s output voltage and wiring polarity. Ensure your sensor matches the sourcing configuration. Test the input with a known good signal source to isolate the issue.

5. Are replacement terminal blocks available for the 1746‑ITV16?
Yes, you can order spare removable terminal blocks under part number 1746‑RTB. This allows pre‑wiring of field devices and quick module swaps without disconnecting individual wires, reducing maintenance downtime.