DS200TCTGG2A | 32-Ch Thermocouple Board

Description

Product Introduction (Anti-Template)

The DS200TCTGG2A is the answer to a specific problem: you have many thermocouples to monitor and limited rack space. This board packs 32 thermocouple inputs into one VME slot—double the channel count of the TCTGG1A, with per-channel cold junction compensation and diagnostic LEDs per channel.

The ‘2’ in the part number tells you this is the ultra-high-density variant in the TCTGG family. Compared to the TCTGG1A (16 inputs, ±0.3°C accuracy, 15ms update), the TCTGG2A gives you twice the channels with slightly lower accuracy (±0.5°C) and a slower update rate (20ms) to manage the higher channel density. If you have 20-32 thermocouples and you’re running out of rack slots, this board solves the problem.

Key Technical Specifications

Compatible Replacement Models

Replacement options depend on your channel count and accuracy requirements.

✅ Drop-in Replacement: The DS200TCTGG2 (no ‘A’) is a direct drop-in with identical 32 inputs, but without diagnostic LEDs and with lower accuracy. If you don’t need diagnostics, the base model is a cheaper option (typically 20-30% less). The ‘A’ is the enhanced version.

⚠️ Software Compatible: The DS200TCTGG1A (16 inputs, ±0.3°C accuracy) provides half the channels with better accuracy. Only use if you don’t need 32 channels.

⚠️ Software Compatible: The DS200TCCBG2A (16 inputs, 14-bit, shared CJC) provides 16 channels with lower accuracy and shared CJC. Only use if you can tolerate shared CJC.

❌ Hardware Incompatible: Any general-purpose analog input board (TCCAG1 series) uses different backplane pins and is not suitable for thermocouple signals.

Frequently Asked Questions (FAQ)

What’s the difference between the TCTGG2A and the TCTGG1A?

The TCTGG1A has 16 thermocouple inputs with per-channel CJC, ±0.3°C accuracy, and a 15ms update rate. The TCTGG2A has 32 thermocouple inputs with per-channel CJC, ±0.5°C accuracy, and a 20ms update rate—double the channels with slightly lower accuracy and slower update.

Why doesn’t this board support R, S, or B thermocouples?

The TCTGG2A uses a 15-bit effective ADC (oversampled 14-bit) that doesn’t have the dynamic range to accurately measure R, S, and B thermocouples (used for high-temperature measurements above 1000°C). The board is designed for general-purpose temperature monitoring (J, K, T, E, N), not for high-temperature exhaust measurements.

Can I use this board with a Mark VIe controller?

No—the TCTGG2A uses the older Mark VI backplane pinout. Mark VIe uses a different assignment and typically uses the IS200TCTGG2A for high-density thermocouple inputs. Use the Mark VIe-specific board for new installations.

How do I test this board before installation?

Testing the TCTGG2A requires checking all 32 channels:

1. Visual inspection: Check for burnt components. Look for diagnostic LEDs.
2. Power-up test: Apply power. All diagnostic LEDs should briefly flash during POST.
3. Firmware check: Read firmware via ToolboxST—should be 3.0 or later.
4. CJC test: With no thermocouple connected, read the CJC temperature for each channel. They should all match ambient within ±0.2°C.
5. Input test: Apply 10.00mV to input 1—read 250°C ± 0.5°C. Repeat for inputs 1-32.
6. Diagnostic LED test: Disconnect a thermocouple—LED should flash amber or red.
7. Isolation test: Measure resistance between input channels—should be >10MΩ.

What’s the most common failure on this board?

Two issues specific to the ultra-high-density thermocouple design:

1. CJC sensor drift. The CJC sensors can drift over time—symptom: a consistent offset on all channels.
2. Multiplexer failure. The TCTGG2A uses a multiplexer to handle 32 channels—if it fails, you’ll get erratic readings on specific channels.

If I’m using this board in a SIL-rated safety application, what’s the recommended maintenance interval?

The high-density thermocouple inputs and per-channel CJC make this board suitable for SIL-1 and SIL-2 applications (not SIL-3). We recommend:

• Visual inspection: Every 6 months (check diagnostic LEDs)
• Power-up test: Every 12 months
• CJC test: Every 12 months
• Input accuracy check: Every 12 months (0.5°C spec)
• Isolation check: Every 2 years
• Full calibration: Every 5 years

What’s the lead time for a replacement TCTGG2A?

These boards are less common than the TCTGG1A:

• New surplus: 3-6 weeks.
• Refurbished: 2-3 weeks. Ensure the refurbisher tests all 32 channels.
• Used/as-is: High risk—the multiplexer is a wear item.

Is there a direct Mark VIe equivalent?

Yes—the IS200TCTGG2A (Mark VIe version). The backplane pinout is different.

What termination board should I use with the TCTGG2A?

The TCTGG2A is designed to interface with the DS200TBCEG2 (high-density thermocouple termination board) or the DS200TBCBG2A (high-density thermocouple termination board). The termination board provides the 32 CJC sensors and the terminal connections.

What’s the update rate for this board?

The TCTGG2A samples all 32 channels simultaneously at 20ms intervals—50Hz update rate. This is slower than the TCTGG1A (15ms) due to the higher channel density.

What’s the maximum cable length for thermocouples on this board?

GE recommends a maximum of 200 feet (60 meters) for thermocouple cable runs—shorter than the TCTGG1A (300 feet) due to the lower input impedance (>5MΩ vs. >10MΩ). For critical temperature measurements, keep cable runs as short as possible.

ICS TRIPLEX9852/9802
ICS TRIPLEX9852
ICS TRIPLEX9852