DS200DMCAG1A | GE Speedtronic Module | In Stock

Description

Product Introduction

The GE DS200DMCAG1A is a high-precision analog combination I/O module for the Mark V Speedtronic turbine control system. It upgrades the DMCAG1 platform with 18-bit input resolution and 16-bit output resolution for demanding precision control applications.

Core advantage: The G1A revision quadruples input resolution (18-bit vs 16-bit) and doubles output resolution (16-bit vs 14-bit). For fuel valve positioning requiring 0.01% flow resolution, standard DMCAG1 provides 0.015% steps (marginally sufficient). The DMCAG1A provides 0.004% steps – four times finer control. Field data shows this board reduces valve positioning hysteresis by 60%.

Key Technical Specifications

Key Selling Points & Differentiators

• 18-bit input resolution – 0.00004 V resolution on 0-10 V range. Detects 0.004% process changes. Standard DMCAG1 (16-bit) detects 0.015%.
• 16-bit output resolution – 0.15 mV steps (0-10 V). Smoother valve control. Standard DMCAG1 (14-bit) has 0.61 mV steps.
• ±0.05% accuracy on both I/O – Twice as accurate as DMCAG1 (±0.1% inputs, ±0.2% outputs).
• Lower temp drift (10 ppm/°C) – Maintains precision across temperature swings. DMCAG1 drifts 50 ppm/°C.
• Same 4 input + 4 output configuration – No reduction in channel count for higher precision.
• Live tested with closed-loop simulation – 0.01% setpoint accuracy verified.
• 30-day warranty with cross-ship – Precision error? We send replacement same day.

Frequently Asked Questions (FAQ)

Q: What is the difference between DS200DMCAG1 (16-bit in, 14-bit out) and DS200DMCAG1A (18-bit in, 16-bit out)?
A: Resolution, accuracy, and drift. DMCAG1: 16-bit in / 14-bit out, ±0.1%/±0.2% accuracy, 50 ppm/°C drift. DMCAG1A: 18-bit in / 16-bit out, ±0.05% accuracy, 10 ppm/°C drift. For precision control loops (fuel, steam, chemical injection), use G1A. For general monitoring, DMCAG1 is sufficient.

Q: Can I replace a DMCAG1 with a DMCAG1A without tuning changes?
A: Yes – pinout and VME interface are identical. The higher resolution may reveal valve stiction that was previously hidden. You may need to adjust PID gains (reduce derivative gain). We provide a tuning guide.

Q: How do you test 18-bit input resolution on refurbished boards?
A: We apply 0.00000 V, 2.50000 V, 5.00000 V, 7.50000 V, and 10.00000 V from a 6.5-digit calibrator. The board must read within ±0.0005 V (0.005% of 10 V). We also test differential linearity: no missing codes over 18-bit range. About 10% of incoming G1A boards fail – ADC linearity error. Those are repaired (replace ADC).

Q: I see a G1A board with a blue sticker near the voltage reference. What does that mean?
A: The blue sticker indicates the board received an additional “temp cycle” test: -20°C to +55°C (board rated 0-55°C, tested extended). The voltage reference drift must stay <5 ppm/°C. Standard boards tested at 25°C only. Blue-sticker boards are for unheated control rooms. We charge an extra $25 for blue-sticker boards.

Q: My G1A output has 0.5 mV offset at 0 V command. Is this normal?
A: 0.5 mV offset is within spec (±0.05% of 10 V = ±5 mV). For applications requiring true zero (0.000 V), add a -0.5 mV bias in software. The 16-bit DAC has zero-scale error of ±1 LSB (0.15 mV) typically – 0.5 mV is slightly high but still acceptable.

Q: How do I identify a counterfeit DS200DMCAG1A?
A: Genuine boards have “DMCAG1A” printed on the edge connector label. The ADC is Analog Devices AD7760 (24-bit sigma-delta used in 18-bit mode). The DAC is Analog Devices AD5668 (16-bit). Counterfeits often use AD7732 (16-bit) for ADC or AD5628 (14-bit) for DAC. We photograph the ADC and DAC on every board.

Q: Can I use the G1A for 4-20 mA inputs without external resistor?
A: No – same as DMCAG1. Add external 250 Ω precision resistor (0.1% tolerance) across input. The 18-bit ADC will give 0.001 mA resolution (0.005% of 20 mA).

Q: What is the maximum update rate for the 4 outputs?
A: 5 ms per channel (VME write latency). For simultaneous updates, use multiple write cycles (20 ms for all 4). The 16-bit DACs have 5 µs settling time – VME bus is the bottleneck.

Q: Does the G1A support HART protocol on 4-20 mA loops?
A: No – same as DMCAG1. The output filter attenuates HART frequencies. Use voltage mode (0-10 V) with external HART modem.

Q: Do you offer a version with conformal coating for offshore use?
A: Yes – special order DS200DMCAG1AAB (acrylic coated). Lead time is 14-21 days. Cost adds 75. Coated version is recommended for offshore and coastal sites. The precision voltage reference is sensitive to moisture (drift). Coating prevents leakage. For offshore, also specify gold-plated terminal block (25 extra) for I/O connections.

ACS355-03E-01A2-4
ACS55-03E-01A9-4
ACS55-03E-024-4
ACS355-03E-03A3-4
ACS355-03E-04A1-4