AH04PT-5A DELTA AH500 Series 4-Channel RTD Temperature Module

Product Overview

The AH04PT-5A (AH04PT5A) is a high-precision 4-channel RTD temperature measurement module designed for the Delta AH500 modular PLC platform. This module serves as a critical interface for thermal monitoring in sophisticated B2B industrial environments, supporting a wide range of Resistance Temperature Detectors (RTD) including PT100, PT1000, Ni100, and Ni1000. With an effective 16-bit resolution and integrated PID control capabilities, the AH04PT-5A allows for autonomous temperature regulation, reducing CPU overhead while ensuring process stability. Its robust design features signal isolation and disconnection detection, making it an ideal choice for sectors requiring high reliability, such as plastic injection molding, pharmaceutical manufacturing, and HVAC climate control.

Technical Configuration

The AH04PT-5A architecture is built around flexibility and diagnostic depth. It accommodates 2, 3, and 4-wire RTD configurations, allowing engineers to balance wiring costs against measurement accuracy. The module features a 150 ms conversion time per channel for 2/4-wire setups and includes a JIS-type removable terminal block for secure, vibration-resistant industrial wiring. Beyond simple data acquisition, the AH04PT-5A supports hot-swapping, enabling module replacement without system shutdown, and provides a built-in interrupt function that triggers the PLC CPU immediately if temperature thresholds are breached, ensuring rapid response to critical thermal events.

Technical Specifications

Technical FAQs

How do I choose between 2, 3, or 4-wire RTD modes for the AH04PT-5A?

Use 4-wire mode for the highest precision as it completely eliminates lead-wire resistance. 3-wire is the industry standard for balancing cost and accuracy over medium distances, while 2-wire should only be used for very short distances where wire resistance is negligible or accuracy requirements are lower.

What happens if a sensor wire breaks or a probe fails?

The AH04PT-5A includes a "Disconnection Detection" function. Upon a sensor failure, the module status LED will indicate a fault, and a specific diagnostic bit is set in the PLC register, allowing the system to trigger a safe-state shutdown or an alarm.

Can this module perform temperature control without a separate PID block in the PLC code?

Yes. The AH04PT-5A has built-in PID functionality. By configuring the setpoint and tuning parameters directly within the module's configuration, it can handle the control logic internally, which provides faster and more consistent thermal regulation.

Engineering & Installation Guide

• Lead-Wire Compensation: When using 3-wire RTDs, ensure all three wires are of identical length, gauge, and material. The AH04PT-5A calculates temperature based on the resistance difference; unbalanced wires will introduce a constant temperature offset that degrades measurement accuracy.

• Noise Mitigation: RTD signals are extremely sensitive to electromagnetic interference. Always use shielded cables and ground the shield at the PLC side. Avoid routing RTD cables in the same tray as high-current motor leads or 460V power lines to prevent signal "jitter" or false disconnection alarms.

• Hot-Swapping Protocol: While the AH04PT-5A supports hot-swapping, ensure the replacement module is the exact same model number and hardware revision. Before removal, verify the "Module Status" LED to ensure no critical control processes are in a state that would be rendered unsafe by a momentary loss of feedback.