DS3800XTIA1A1B | GE OEM Mark VIe Terminal Board

Description

Product Introduction

The DS3800XTIA1A1B is the ruggedized, high-accuracy counter board in GE’s Mark VIe line—100 kHz count rate, 32-bit accumulators, and a thick epoxy conformal coating. The “1A1B” suffix tells you this is a later production run with improved gate time accuracy (0.01% vs. 0.05% on the base XTIA) and a heavy epoxy layer—the same salt-spray-resistant coating you’d spec for offshore or chemical plant equipment.

This board is the top choice for totalization in corrosive environments. It counts pulses from flow meters, encoders, and event sensors with 32-bit resolution—no overflow concerns for hours of counting—and the epoxy coating protects against salt spray, chemical vapors, and extreme humidity. The improved gate time accuracy means your totalized counts are more precise over long periods, which matters for flow totalization and custody transfer applications. Typical buyers are plant engineers in coastal, offshore, or chemical facilities who need reliable pulse accumulation without the failure modes of uncoated boards.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: Can I hot-swap this board?

No. The Mark VIe backplane does not support live insertion. Power down the entire I/O pack before removal. The counter registers can corrupt if you hot-plug.

Q: How is the 1A1B different from the base XTIA?

Three upgrades:

• Gate time accuracy: The 1A1B has ±0.01% gate time accuracy (versus ±0.05% on the base XTIA). That’s a 5x improvement—important for flow totalization and custody transfer.
• Conformal coating: The “B” suffix indicates thick epoxy coating. The base XTIA has no coating.
• Component updates: The “1A” revision uses a specific batch of timing crystals and counter ICs with tighter tolerance.

The 100 kHz count rate, 32-bit counters, and programmable thresholds are identical.

Q: What’s the difference between the “A” and “B” coating on this board?

On GE’s conformal coating scale:

• “A”: Acrylic coating (25-35µm). Good for moderate humidity, dust protection.
• “B”: Thick epoxy coating (75-100µm). Salt spray resistant, better for coastal, offshore, or chemical environments.

The epoxy coating traps more heat—the board runs about 2-3°C warmer at full load. The “B” coating also adds about 3-5 grams to the board weight.

Q: How does the improved gate time accuracy help?

The gate time is the period over which the board counts pulses. If the gate time is off by 0.05%, your totalized count will be off by 0.05%. Over a 24-hour period at 100 kHz, that’s:

• 0.05% error = 0.0005 * 8.64 billion pulses = 4.32 million pulses error
• 0.01% error = 0.0001 * 8.64 billion pulses = 0.864 million pulses error

For flow totalization, that’s the difference between accurate billing and being off by thousands of gallons. The 0.01% accuracy matters for custody transfer applications.

Q: How do you test this board before shipping?

We run a 7-step test with a precision pulse generator up to 100 kHz and a GPS-disciplined timebase to verify gate time accuracy:

• Visual inspection: Check for cracked connectors, burnt traces, swollen capacitors. Verify the epoxy coating is uniform and covers all components.
• ESD check: Insulation resistance between channels and chassis ground >10MΩ.
• Power-up: Apply +5V DC, measure current draw (1.5A ±10%).
• Communication handshake: Simulate backplane connection, verify board ID.
• Gate time accuracy test: Set gate time to 1 second, inject 100 kHz, and measure the count over 100 cycles. Verify the average count is 100,000 ±0.01% (that’s ±10 counts).
• Counter accuracy test: Inject 1 million pulses at 100 kHz (10 seconds). Verify the board counts exactly 1,000,000 ±0.01%.
• 24-hour soak: Run at 50°C ambient with all channels counting at 100 kHz. Log counter values every hour—failure threshold is >0.01% deviation.

We reject about 4% of these boards—the improved accuracy is great, but the timing crystals are sensitive to thermal drift.

Q: What’s the most common failure on this board?

Four things specific to the enhanced accuracy and epoxy-coated design:

• Timing crystal drift: The gate time accuracy depends on a precision oscillator. Over time, the crystal can drift. We replace crystals on about 10% of refurbished units.
• Optocoupler burnout: The input optocouplers can fail if subjected to over-voltage. We replace them on about 10% of units.
• Counter register corruption: If power is interrupted during a count cycle, the register can freeze. We test by power-cycling during active counting.
• Coating-related heat stress: The epoxy coating traps heat, which can stress the timing crystal over time. We monitor temperature closely during the soak.

Q: What’s the maximum count I can accumulate?

32 bits = 4,294,967,295 counts. At 100 kHz, that’s 11.93 hours of counting before overflow. For most applications, you’ll reset the counter before it overflows. If you need longer totalization, implement software rollover handling.

Q: What cable should I use for the inputs?

Shielded twisted-pair. For 100 kHz signals, use:

• 24 AWG or thicker for runs under 50 meters
• 22 AWG for runs up to 100 meters
• Shield grounded at the rack side only

The XTIA’s programmable threshold lets you accommodate different signal levels—just set the threshold to half the signal amplitude.

Q: Can I use this board for flow totalization?

Yes—that’s a primary application. The 32-bit accumulator and 0.01% gate time accuracy make it ideal for:

• Gas flow meters (pulses per standard cubic foot)
• Liquid flow meters (pulses per gallon)
• Steam flow meters (pulses per pound)

The 100 kHz count rate handles most turbine and positive displacement meters.

Q: Are there counterfeit versions of this board?

Yes. Look for:

• Counter IC: Genuine boards use a high-speed 32-bit counter IC (e.g., Xilinx CPLD or TI counter). Counterfeits use generic 16-bit counters and fake the 32-bit resolution.
• Timing crystal: Genuine boards use a precision crystal (±50 ppm). Counterfeits use standard crystals (±100 ppm)—the gate time accuracy will degrade.
• Optocouplers: Genuine high-speed optocouplers. Counterfeits use slower optocouplers that miss high-frequency pulses.
• Coating: Genuine epoxy coating is thick, uniform, and slightly yellowish. Fakes use thinner coatings that are clear or uneven.
• Label: Genuine—matte finish, greenish barcode. Fakes—glossy.

We trace stock to decommissioned assets. If buying elsewhere, demand photos of the component side and serial sticker, especially close-ups of the counter IC and timing crystal.

Q: What’s your warranty?

1-year against functional defects. For counter boards, we guarantee the counter accuracy and gate time accuracy for the warranty period—if either drifts out of spec, we’ll recalibrate or replace it. For coated boards, if the coating fails (delamination, cracking) within the warranty period and hasn’t been physically damaged, we’ll also replace it.

Q: What’s the lead time?

We typically carry 1-3 units. Orders before 2 PM EST ship within 1-2 business days after testing. The 24-hour soak is mandatory—we won’t skip it. Expedited shipping available with waiver. For custody transfer applications, we strongly recommend waiting for the full test cycle—the timing crystal only shows drift after hours of thermal stress, especially with the heat-trapping epoxy coating.

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