1. Core Product Function

1. Receive digital command data from DPU main controller via VME Multibus backplane;

2. Convert digital signal into standard industry analog control signal to drive field actuator, servo valve, positioner, feedwater regulating valve;

3. Built-in D/A conversion, signal isolation, output short-circuit protection & fault feedback to rack controller;

4. Work cooperatively with QRD analog input board to form closed-loop regulation loop for steam turbine speed, load, oil pressure & valve opening control.

2. Channel & Electrical Specifications

Channel Definition

• Total: 4 galvanically isolated independent analog output channels

• Standard factory default configuration: 4–20mA DC current loop output; configurable via onboard jumpers for DC voltage output: 0~5VDC / 0~10VDC / ±10VDC

Key Electrical Parameters

• Powered by crate backplane: +5VDC, ±12VDC (supplied by MDPS 3A99116G01 power board)

• D/A Resolution: 16-bit high precision conversion

• Output Load: Max 500Ω load resistance for 4–20mA current output

• Channel Isolation: ≥1500VAC isolation between backplane side and field wiring per channel

• Output Accuracy: ≤±0.2% FS full scale error at rated operating temperature

Protection Functions

• Short-circuit auto current limiting for each output channel

• Undervoltage/overvoltage lockout protection from abnormal backplane power fluctuation

3. Environmental Rating

• Operating Temperature: 0℃ ~ +55℃ (inside control cabinet)

• Storage Temperature: -40℃ ~ +85℃

• Ambient Humidity: 5%~95%RH non-condensing, no corrosive gas, conductive dust

• EMC: Onboard multi-stage EMI filtering for power plant cabinet heavy interference environment, comply with CE industrial control standard

4. Installation & Replacement Guide

1. Standard Q-Line plug-in design, install into vacant VME rack slot of 9-slot Q-crate; backplane auto power & bus connection after insertion

2. Direct drop-in replacement for same QCA G-version boards without cabinet wiring modification

3. Post-replacement operation: No-load power on first, calibrate zero & full-scale output via front panel test terminals before connecting field actuator loads

5. Application Range

• Valve servo drive analog output for main steam valve, control oil actuator, feedwater regulation loop

• Matching full set Q-Line modules: QRD analog input(3A99114Gxx), QSR servo drive(3A99101Gxx), QRF RTD input(3A99109G01), MDPS power board(3A99116G01)

6. Commercial & Maintenance Info

• Original OEM production discontinued globally; available stock: tested refurbished / used inspected spare parts

• Standard repair lead time: 2~4 weeks, emergency rush repair available; global delivery via DHL/UPS/FedEx

7. Common Troubleshooting

1. All channels no output: Check backplane +5V/±12V power from 3A99116G01 MDPS board, rack fuse

2. Single channel zero drift: Re-cal zero/span at front test port, inspect field load short circuit

3. Output signal jitter/fluctuation: Verify jumper setting matches output type, check cabinet grounding & field cable anti-interference