Description
Honeywell 620-0049
Technical Specifications
- Channel Quantity: 8 RTD input channels
- Supported Sensor: PT100, PT1000, Cu50
- Wiring Mode: 2-wire, 3-wire, 4-wire configurable per channel
- Excitation Current: 0.5 mA constant current per channel
- ADC Resolution: 16-bit
- Measurement Accuracy: ±0.15 °C full measurement range
- Channel Group Isolation: 500 VAC reinforced isolation
- Backplane Interface: IPC620 I/O Link backplane bus
- Operating Temperature: 0 °C to +60 °C
- Power Consumption: 5.4 W maximum
- Hot Swap Support: Yes
Functional Features Software configurable wiring mode to compensate wire resistance error for 2-wire and 3-wire RTD. Per-channel open circuit and short circuit fault detection for RTD sensor cable. Built-in RTD characteristic curve lookup table for direct temperature conversion. Digital low-pass filter suppresses electromagnetic noise on resistance signal. Front panel LED indicates module power, bus communication and group fault. Temperature value can be output in Celsius or Fahrenheit unit. All temperature data frames carry CRC checksum for communication verification.
Application Scenarios PT100 temperature measurement of pipeline, tank and reactor in chemical plant Motor bearing and winding temperature monitoring of pump and fan unit HVAC chilled water and hot water pipeline temperature collection Heat treatment furnace auxiliary temperature monitoring IPC620 PLC multi-point RTD temperature acquisition spare replacement
Performance Parameters
- ADC conversion update rate: 8 Hz per channel
- Isolation withstand voltage: 500 VAC for 60 seconds
- Common mode rejection ratio: 90 dB minimum
- Wire break detection response: Less than 250 ms
- Temperature drift of excitation circuit: ±20 ppm / °C
Material Composition Multilayer FR4 PCB, 16-bit ADC chip, precision constant current source circuit, instrumentation amplifier, optocoupler isolators, low drift metal film resistors, TVS surge diodes, gold-plated backplane edge connector, UL94 V0 flame retardant plastic front panel.
Structural Features Standard plug-in eurocard form factor matching IPC620 rack slot. Rear gold edge connector mates with IPC620 backplane I/O Link bus. Internal isolation barrier separates RTD resistance signal zone and digital logic zone. Front panel LED array shows module running state and fault alarm. Anti-keying notch prevents reversed insertion into thermocouple or analog current slot. Constant current excitation traces are isolated from high noise digital bus traces.
Working Principle Onboard precision constant current source injects stable small current into RTD sensor. The resistance of RTD changes with temperature, generating voltage drop proportional to temperature. Instrumentation amplifier amplifies weak voltage signal and sends it to ADC for digital sampling. FPGA chip uses configured RTD type and wiring compensation parameter to calculate accurate temperature value, and judges whether the channel is open or short circuit according to measured resistance range. Temperature value and fault flag are packed into I/O Link frame and uploaded to IPC620 CPU.
Installation Requirements Use matched RTD extension cable, keep extension cable away from high current AC power cable. Select corresponding wiring mode parameter in software according to on-site actual wiring. 4-wire wiring mode provides the highest measurement precision for long distance sensors. Avoid direct hot air blowing to the module terminal block to stabilize internal reference circuit. Check temperature reading with handheld RTD calibrator during commissioning.
Usage Notes 2-wire RTD wiring will bring wire resistance error, which needs parameter compensation. Short circuit of RTD cable will trigger low temperature fault alarm. Do not apply external voltage directly to RTD input terminals. Constant current excitation circuit cannot be modified or shorted.
