General Electric HE693THM884 8-Channel Thermocouple Input Module

Description

The HE693THM884 is an 8-channel thermocouple input module designed for the GE Fanuc Series 90-30 PLC platform. Manufactured by Horner APG, this module provides high-precision temperature monitoring by allowing direct connection of J and K type thermocouples to the PLC backplane, eliminating the need for external signal conditioners or transmitters. With an 18-bit integrating A/D converter and a resolution of 0.1 degC, it is engineered for demanding industrial temperature sensing applications.

Features

• 8 isolated input channels for J and K type thermocouples
• High-resolution 18-bit A/D conversion with 0.1 degC precision
• Integrated cold junction compensation via terminal block temperature sensing
• Open-circuit detection with dedicated alarm bits for each channel
• Fast data acquisition with a scan rate of up to 40 channels per second
• Direct backplane power consumption of 100mA at 5VDC

Technical Specifications

Installation Guidelines

• Ensure the PLC is powered down before inserting or removing the module from the rack.
• Use shielded thermocouple extension wire to minimize noise interference in industrial environments.
• Connect the cable shield to a reliable earth ground point to maintain signal integrity.
• Avoid routing thermocouple signal cables near high-voltage lines or high-EMI sources (e.g., VFDs, contactors).
• Verify that the terminal block is properly seated to ensure accurate cold junction compensation.

FAQ

What does the HE693THM884 do?

It is an analog input module that allows 8 thermocouples to be connected directly to a Series 90-30 PLC, handling the signal processing and cold junction compensation internally.

What is the main power supply required?

The module consumes 100mA at 5VDC, which is supplied directly from the PLC backplane.

How does the module handle broken sensors?

The module includes an open-circuit alarm bit for each of the eight channels, which allows the PLC program to detect and respond to a broken thermocouple wire.