Description
Technical Parameters
- Manufacturer: Honeywell (Enraf Series)
- Model Number: 854.635-79
- Module Type: XPU (Processor Unit) PC Board
- System Compatibility: Enraf 854 ATG (Advanced Tank Gauge) Servo Level Gauges
- Function: Main CPU board for level calculation, servo motor control, and communication logic
- Microprocessor: High-performance embedded controller for real-time inventory measurement
- Interface: Support for Enraf GPU (Gauging Protocol Unit) and serial communication loops
- Operating Voltage: Internal system voltage derived from 854 ATG power supply module
Product Datasheet
| Specification | Details |
|---|---|
| Model | 854.635-79 |
| Origin | Netherlands / USA |
| Dimensions | 16.5 cm x 11.2 cm x 1.5 cm |
| Weight | 0.38 kg |
| Measurement Precision | High-resolution servo feedback processing |
| Connectivity | Multi-pin header for display and I/O integration |
| Operating Temp | -40°C to +65°C |
| Coating | Conformal coating for industrial moisture protection |
Application Fields
The 854.635-79 XPU board is the “brain” of the Enraf 854 ATG system used in:
- Oil & Gas Storage: Precise inventory measurement of crude oil and refined products in bulk storage tanks.
- Chemical Plants: Level and interface measurement for hazardous liquid chemicals.
- Custody Transfer: High-accuracy data processing for commercial fiscal transactions and tank farm management.
- Refineries: Real-time monitoring of product levels and density calculations in high-pressure environments.
Product Instructions
- Safety Precautions: Before opening the explosion-proof housing of the 854 ATG, ensure the power is isolated and the atmosphere is non-hazardous.
- ESD Protection: Use an anti-static wrist strap. The XPU board contains sensitive microprocessors and memory chips.
- Removal: Carefully disconnect the display cable and power ribbons before unscrewing the board from its mounting standoffs.
- Configuration: Transfer the site-specific parameters (tank height, density, zero-points) from the old board or re-program via the Enraf portable terminal or Entis software.
- Reassembly: Ensure the board is firmly seated and all connectors are locked to prevent communication timeouts caused by vibration.
Q&A
Q1: What is the main function of the XPU board in an 854 ATG gauge? A1: The XPU board processes signals from the servo motor and displacement sensor to calculate the exact liquid level, temperature, and volume of the tank contents.
Q2: Can I swap an 854.635-79 board between two different tanks? A2: Physically yes, but you must update the tank-specific configuration data stored in the firmware to ensure accurate measurement readings for the new tank geometry.
Q3: Does this board support HART communication? A3: The XPU handles the core gauging logic; HART or other Fieldbus communications are typically managed via specific interface modules connected to this board.
Recommended Similar Models
- Honeywell Enraf 854.635-42
- Honeywell Enraf 854.635-78
- Honeywell Enraf 854.650-12
- Honeywell Enraf 854.650-80
- Honeywell Enraf 873.635-01
