DS200SDCCG1 | GE Mark V Servo Drive Controller

Description

Product Introduction

The DS200SDCCG1 is a dual-channel servo drive controller board for GE’s Mark V DS200 series, used in Speedtronic turbine control systems. It provides two independent servo control loops on a single board—for applications requiring coordinated control of two valves or actuators (e.g., fuel and bypass valves, or two steam admission valves).

The SDCCG1 is essentially two SDCCF1 controllers on one PCB, sharing backplane power and communication but with independent PID parameters, feedback inputs, and outputs. This saves one rack slot compared to using two single-channel SDCCF boards. It is designed for applications where two valves must operate independently but share space constraints: gas turbine fuel and bypass control, steam turbine high-pressure and intermediate-pressure valve control, or compressor anti-surge valves.

Key Technical Specifications

Shared Parameters (Both Channels)

Key Selling Points & Differentiators

• Two independent servo controllers in one slot – Controls two valves simultaneously. Saves one rack slot versus two SDCCF boards. Ideal for space-constrained cabinets.
• Independent PID per channel – Tune Channel 1 for fuel valve (fast response), Channel 2 for bypass valve (slower response). Parameters stored separately.
• Redundant feedback inputs per channel – Each channel accepts two 4–20 mA position feedback signals (e.g., primary and secondary LVDT). Board uses average or selects best signal (configurable).
• Fast 1 ms update rate on both channels – Both loops run at 1 kHz simultaneously. No scan time penalty for dual channels.
• QC includes dual-channel closed-loop test – Both channels tested simultaneously with simulated loads. Cross-channel interference measured (<0.1% of span).
• Configuration backup available – Send us your old board. We extract configuration for both channels and program into replacement.
• 2-year warranty – Covers both output amplifiers, feedback inputs, and all I/O.

Frequently Asked Questions (FAQ)

Q: What is the difference between SDCCF1 (single channel) and SDCCG1 (dual channel)?

Choose SDCCG1 when you need two independent servo loops in one slot.

Q: Can I replace two SDCCF1 boards with one SDCCG1 without changing my configuration?
A: Yes—but with significant reconfiguration. The SDCCG1 presents as a single backplane device with two sub-channels. Your existing system sees two separate boards at different backplane addresses. You must:

1. Remap I/O addresses in the Mark V configuration.
2. Re-tune PID parameters (they can be copied from old board).
3. Rewire field connections (two SDCCF1 boards have 6 terminal blocks total; SDCCG1 has 4 terminal blocks). Allow 8–12 hours.

Q: Are the two channels isolated from each other?
A: Partially. The field inputs (4–20 mA, LVDT) and outputs (±10 VDC) are isolated from the backplane at 1500 VAC. However, Channel 1 and Channel 2 share a common isolated ground. Isolation between channels is 1000 VAC—sufficient for most applications but not full galvanic isolation. For complete isolation, use two separate SDCCF1 boards.

Q: Can I use one channel for a valve and the other channel for something else (e.g., pressure control)?
A: Yes—the SDCCG1 is a general-purpose servo controller. It does not require the second channel to be a valve. You can configure Channel 1 for fuel valve position and Channel 2 for gas pressure control (using pressure transmitter 4–20 mA feedback, output to I/P converter). Any 4–20 mA or ±10 VDC servo application works.

Q: What happens if one channel fails?
A: The channels are independent except for common backplane power and communication. If Channel 1 output amplifier fails, Channel 2 continues to operate normally. Fault LEDs on front panel indicate which channel failed. The board does not have cross-channel fault propagation unless programmed in the Mark V logic.

Q: What is the maximum scan rate when both channels are active?
A: Both channels update simultaneously at 1 ms (1000 Hz). The processor handles both loops without time-slicing. Total latency (input to output) is 2 ms typical (1 ms for feedback sampling + 1 ms for PID calculation and output).

Q: Can I use the SDCCG1 for a valve with 4–20 mA output (instead of ±10 VDC)?
A: No—same as SDCCF1. Output is ±10 VDC only. Use external voltage-to-current converter (ACC-V2I) per channel.

Q: What QC tests are specific to the dual-channel SDCCG1?
A: Ten tests, all documented per channel:

1. Output calibration (±10 VDC per channel).
2. Feedback calibration (4–20 mA per channel).
3. PID loop test per channel (independent).
4. Cross-channel interference test: Run Channel 1 at full ±10 VDC output, 1 kHz square wave. Measure induced voltage on Channel 2 output. Must be <5 mV peak-to-peak.
5. Simultaneous step response: Apply 10% step to both channels simultaneously. Verify both settle within 200 ms, no interaction.
6. Fault detection per channel.
7. Output short protection per channel.
8. Isolation (field to backplane) and channel-to-channel (1000 VAC).
9. Discrete I/O per channel.
10. Burn-in: 72 hours at +65°C, both channels running continuous closed-loop simulation.

Q: What shipping protection?
A: Anti-static bag, ESD foam cradle, double-wall box. Board is double-width (8HP). Shock indicator. Each board ships individually. Configuration extraction service available.

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