Description
Honeywell 2MLQ-TR4A-CC
Technical Specifications
- Channel count: 4 thermocouple input channels
- Supported types: J, K, T, E, R, S thermocouples
- Resolution: 16-bit ADC
- Cold junction compensation: Automatic integrated sensor
- Backplane interface: MasterLogic 200 expansion bus
- Operating temperature: 0 °C to +55 °C
Functional Features Automatic cold junction compensation, eliminates temperature measurement error. Software-selectable thermocouple type per channel. Open thermocouple detection, triggers channel fault on broken sensor. Digital filter smooths high-temperature signal noise. Module status LED indicates power and fault. Configurable via PLC programming software.
Application Scenarios MasterLogic 200 high-temperature furnace measurement Heat treat oven thermocouple signal acquisition Industrial kiln temperature monitoring Spare part replacement for failed thermocouple input modules
Performance Parameters
- Measurement accuracy: ±0.5 °C over full thermocouple range
- Cold junction compensation accuracy: ±0.2 °C
- Update rate: 50 ms per channel
- Input impedance: 10 MΩ
- Open sensor detection response: ≤200 ms
Material Composition ABS flame retardant housing 16-bit ADC chip Cold junction compensation thermistor Precision instrumentation amplifier Removable screw terminal block Gold-plated backplane connector
Structural Features Narrow rectangular DIN-rail mount housing. Front removable terminal block labeled per thermocouple channel. Side expansion bus connector. Front power and fault LEDs. DIN rail mounting clip.
Working Principle Thermocouple millivolt signals connect to input terminals, routed to the instrumentation amplifier. The amplifier scales the low-level mV signal to the ADC input range. A nearby thermistor measures terminal block temperature for cold junction compensation, correcting for ambient temperature at the thermocouple connection point. The 16-bit ADC converts the amplified signal to digital counts, converted to temperature values per the selected thermocouple type. Open sensor detection monitors input circuit continuity; broken thermocouple triggers a channel fault flag.
Installation Requirements Clip the module to the DIN rail. Connect thermocouple wires using compensated extension cable matching the sensor type. Configure thermocouple type per channel in PLC software. Verify measured temperature matches a calibrated reference after power-up.
Usage Notes Thermocouple extension wire must match sensor type; mismatched cable causes measurement error. Never apply 24 V power to thermocouple inputs, this destroys the amplifier. Terminal block temperature must be measured by the onboard compensation sensor; do not block airflow around the module. Shielded thermocouple cable reduces EMI noise on low-level signals.
