Product Short Description
Product Overview
Plug-in analog output module matched with Honeywell Excel 800 building & industrial distributed control system, providing 8 channels of standard 4–20 mA analog output signals for regulating valves, variable frequency drives and display instruments. Equipped with built-in Hand-Off-Auto (HOA) manual override function to realize local manual adjustment without upper computer operation, requiring supporting XSU821-22 base seat for installation.
Description
Technical Specifications
- Output Channels: 8 analog isolated output channels
- Standard Output Signal: 4–20 mA DC current signal
- Output Load Capacity: Max 750 Ω resistance per channel
- HOA Function: Independent manual adjustment knob per channel, local output signal fine-tuning
- Communication Bus: Honeywell proprietary panel bus, pluggable hot connection
- Power Supply: 24 V DC system bus power supply
- Dimension: 115 mm × 82 mm × 35 mm, weight 0.4 kg
- Operating Temperature: 0 ℃ ~ +60 ℃, indoor cabinet installation only
- Accuracy: ±0.1% full scale analog output precision
Core Functional Features
- Independent HOA manual override switch for every channel, supporting manual valve adjustment during upper computer failure
- Galvanic isolation between all output channels to avoid signal crosstalk between regulating loops
- Automatic loop fault diagnosis including wire breakage and short circuit, fault code uploaded to DCS host
- Pluggable modular design, quick disassembly from XSU821-22 base without rewiring field cables
- Linear signal output calibration function via front panel potentiometer
- LED indicators for channel active state, manual mode and fault alarm
Working Principle
The DCS main controller transmits analog regulation setpoints to XFR822A through the panel bus. The module’s DAC chip converts digital setpoint values into standard 4–20 mA analog current signals and outputs them to field regulating valves. When the HOA switch is toggled to Hand position, the internal potentiometer directly controls output current independent of upper computer commands. The loop sampling circuit monitors output load impedance; if the circuit is open or shorted, the fault light lights up and fault information is uploaded to the DCS monitoring screen. All channel circuits adopt isolated power design to prevent ground loop interference from multiple field regulating equipment.
Structural & Material Characteristics
- Housing: Flame-retardant black ABS plastic shell with dust-proof front panel
- Control circuit: Double-layer FR4 PCB with isolation transformers for each output channel
- Manual operation components: Metal rotary adjustment knobs with locking function to prevent accidental misoperation
Installation Requirements
- Must be inserted into matched XSU821-22 base seat; cannot be installed directly on DIN rail
- Installed in indoor DCS control cabinet only, not suitable for outdoor or explosion-proof hazardous areas
- Analog output cables adopt shielded twisted pair wire, separated from power wiring trough
Application Scenarios
HVAC central air conditioning water valve regulation, building energy management temperature control, small chemical plant flow regulating valve control, boiler auxiliary equipment frequency converter analog setpoint output, factory workshop ventilation system automatic adjustment.
Operation & Maintenance Precautions
- Manual adjustment knobs need locking after operation to avoid accidental touch causing process parameter deviation
- Conduct full output signal calibration every 12 months to maintain ±0.1% precision
- Do not connect voltage input signals to output channels, which will damage internal DAC circuits
- Regularly clean dust on front panel HOA knobs to prevent poor contact of internal potentiometers
Reviews
There are no reviews yet.