Description
Foxboro P0700AB
Technical Specifications
- Component Model: P0700AB
- Channel Configuration: 8 Analog Input (AI) channels
- Signal Type: Multiple thermocouple types and millivolt (mV) signals
- Bus Interface: 2 Mbps Redundant Fieldbus
Functional Features
- High-Precision Cold Junction Compensation: Features a built-in isolated RTD reference junction to completely eliminate ambient temperature measurement errors.
- Burnout Detection: Each channel independently detects thermocouple open circuits to generate timely and accurate alarms.
- Complete Electrical Isolation: Ensures full galvanic isolation between channels, the fieldbus, and ground.
- Sigma-Delta Conversion: Utilizes advanced digital filtering to effectively reject power line frequency noise and interference.
Application Scenarios
Extensively used in high-temperature measurement applications across petrochemical and power generation industries, including boiler furnaces, chemical reactors, and exhaust pipes.
Performance Parameters
- Update Rate: New readings generated every 25ms with configurable integration periods.
- Signal Accuracy: Extremely high precision with minimal conversion error.
- Protection Rating: IP20
Material Composition
Encased in a rugged extruded aluminum housing for superior EMI shielding. Internal PCBs are conformally coated to withstand harsh industrial environments.
Structural Characteristics
Compact FBM design featuring integrated red/green LED status indicators. The precision backplane connector securely supports hot-swapping without disrupting the redundant fieldbus.
Working Principle
Thermocouple mV signals are amplified and converted via a Sigma-Delta A/D converter. The signal is then combined with cold junction compensation data and linearized according to standard thermocouple tables before being transmitted over the fieldbus.
Installation Requirements
Use dedicated thermocouple extension wire or shielded twisted pair cables. The shield must be grounded at the cabinet side only. Never route these cables parallel to high-voltage power lines.
Precautions for Use
Verify thermocouple polarity and type match the software configuration exactly. Never apply external voltage or current signals to this module. Always place the node in “Maintenance Mode” before replacement.
