The IS200TVIBH2B is a Vibration Input Terminal Board designed by General Electric (GE) for its Mark VI gas turbine control system. This board is the version within the TVIB series specifically dedicated to vibration monitoring. Its primary function is to receive signals from up to 14 vibration probes. Through the VVIB processor board, the displacement and velocity signals are digitized and finally transmitted via the VME bus to the controller, enabling real-time monitoring and protection of gas turbine shaft vibration.
Compared to the standard H1A version, the most notable feature of the IS200TVIBH2B board is its front panel equipped with BNC connectors, allowing portable vibration data collection equipment to be connected for predictive maintenance purposes. Additionally, the board provides dedicated connectors for permanent connection to Bently Nevada vibration monitoring equipment, enabling continuous measurement and analysis of turbine vibration.
The IS200TVIBH2B board supports the following types of Bently Nevada probes:
Proximity Probes: For measuring shaft vibration displacement
Velocity/Velomitor Probes: For measuring vibration velocity
Accelerometer Probes: For measuring vibration acceleration
Seismic Probes: For measuring absolute vibration
Phase/Keyphasor Probes: For measuring speed and phase
In the Mark VI system, the IS200TVIBH2B works with the VVIB processor board and supports both simplex and TMR (Triple Modular Redundant) applications. In simplex systems, two TVIB boards connect to the VVIB board via two cables. In TMR systems, the TVIB board connects to three VVIB processors (R, S, T) via three cables.
The board designs the demands of industrial field applications. Jumpers JP1-JP8 configure the probe type for the first eight probes to accommodate different monitoring requirements. The board dimensions are a standard 33.0 cm × 17.8 cm, suitable for installation in standard control cabinets.
II. Main Functions
The primary functions of the IS200TVIBH2B include, but are not limited to, the following:
1. Multi-Type Vibration Probe Interface
The IS200TVIBH2B board can interface with up to 14 vibration probes, covering various types including proximity probes, velocity probes, accelerometers, seismic probes, and keyphasor probes. Each probe connects to the two terminal blocks on the board via three wires.
2. Signal Conditioning and Transmission
Probe input signals are initially conditioned by the IS200TVIBH2B board and then transmitted via cables to the VVIB processor board. The VVIB board performs high-speed sampling and digitization of the displacement and velocity signals. The data is then sent to the controller via the VME bus.
3. BNC Interface for Predictive Maintenance
The IS200TVIBH2B board features 14 BNC connectors on its front panel, providing buffered outputs of the probe signals. These buffered outputs have unity gain, 10 Ω internal impedance, and can drive loads up to 1500 Ω. Portable vibration data collection equipment can connect to these BNC interfaces for predictive maintenance and offline analysis.
4. Bently Nevada System Interface
The board features connectors JA1, JB1, JC1, and JD1 for permanent connection to a Bently Nevada 3500 vibration analysis system. The signal amplitude accuracy for buffered outputs to the Bently Nevada system is 0.1%, ensuring high-precision vibration analysis.
5. Probe Type Configuration
Jumpers JP1A through JP8A on the board configure the probe type for the first eight probes. Each jumper can select one of four types:
S: Seismic probe
V: Velocity probe
P: Proximity probe
A: Accelerometer probe
6. Redundant Power Supply and Protection
The IS200TVIBH2B board uses a -28 V dc bus for power. Regulators provide individual excitation sources for each probe, with a voltage range of -23 to -26 V dc and short-circuit protection. The power supply for each probe is current-limited to 12 mA.
7. High-Speed Sampling
The VVIB processor board samples probe inputs at high speed over discrete time periods, ensuring the accuracy and real-time nature of the vibration data.
8. Threshold Monitoring and Alarming
VVIB performs hardware high/low limit checks and software system high/low limit checks on the probe input signals. A probe fault, alarm, or trip condition occurs if either probe in an X and Y probe pair exceeds its limits. Position inputs for thrust wear protection, differential expansion, and eccentricity are monitored similarly, but only the DC component is used for position indication.
III. System Applications
1. Application in Mark VI Systems
In the Mark VI system, the IS200TVIBH2B works with the VVIB processor board to form a complete vibration monitoring system:
Probe Signal Input: Up to 14 Bently Nevada vibration probes connect to the IS200TVIBH2B via terminal blocks.
Signal Processing: The VVIB board performs high-speed sampling and digitization of probe signals.
Data Transmission: Processed data is sent to the controller via the VME bus.
Monitoring and Protection: The controller performs threshold monitoring, alarming, and trip protection based on vibration data.
2. Simplex System Configuration
In a simplex system, two TVIB boards are required:
3. TMR System Configuration
In a Triple Modular Redundant system, the TVIB board connects to three independent VVIB processors via three connectors:
JR1: Connects to the R controller's VVIB.
JS1: Connects to the S controller's VVIB.
JT1: Connects to the T controller's VVIB.
This redundant configuration ensures that vibration monitoring functions continue even if a single processor fails.
4. Integration with Bently Nevada Systems
The IS200TVIBH2B board can be permanently connected to a Bently Nevada 3500 vibration analysis system via connectors JA1, JB1, JC1, and JD1. This integration allows:
Utilization of advanced analysis functions from the Bently Nevada system.
Data sharing with third-party monitoring systems.
High-precision data for offline analysis and fault diagnosis.
5. Predictive Maintenance Applications
The unique BNC interface of the IS200TVIBH2B facilitates predictive maintenance:
Portable data collection equipment can be connected at any time without system shutdown.
Offline vibration analysis and fault diagnosis are possible.
Supports periodic inspections and trend analysis.
6. Typical Application Scenarios
Gas turbine shaft vibration monitoring
Steam turbine shaft vibration monitoring
Compressor vibration monitoring
Generator vibration monitoring
Predictive maintenance for rotating machinery
IV. Interface and Probe Configuration
1. Probe Connection
The IS200TVIBH2B board has two terminal blocks for connecting up to 14 vibration probes. Each probe uses three wires for power, signal, and common connections. Probe types include:
Proximity probes
Velocity probes
Accelerometer probes
Seismic probes
Keyphasor probes
2. Probe Type Configuration Jumpers
Jumpers JP1A through JP8A on the board configure the probe type for the first eight probes. Each jumper can be set to one of four positions:
| Jumper Setting | Probe Type | Description |
| S | Seismic | For measuring absolute vibration |
| V | Velocity | For measuring vibration velocity |
| P | Proximity | For measuring shaft vibration displacement |
| A | Accelerometer | For measuring vibration acceleration |
Note: The type for probes 9-14 may be determined by other configuration methods or by referring to specific system design documents.
3. Connector Description
| Connector | Type | Purpose |
| JR1 | 7-pin D-type | Connection to VVIB board (for simplex systems) |
| JS1 | 7-pin D-type | Connection to S controller VVIB (for TMR systems) |
| JT1 | 7-pin D-type | Connection to T controller VVIB (for TMR systems) |
| JA1 | Dedicated | Connection to Bently Nevada system |
| JB1 | Dedicated | Connection to Bently Nevada system |
| JC1 | Dedicated | Connection to Bently Nevada system |
| JD1 | Dedicated | Connection to Bently Nevada system |
| BNC1-14 | BNC | Buffered outputs for portable equipment connection |
4. Buffered Outputs
The 14 BNC connectors provide buffered outputs of the probe signals with the following characteristics:
Gain: Unity (1:1)
Output Impedance: 10 Ω
Drive Capability: Can drive loads up to 1500 Ω
Purpose: Connection of portable vibration analyzers, data collectors, or recording equipment
V. Diagnostics and Maintenance
1. Diagnostic Functions
The VVIB processor board performs the following diagnostics on the IS200TVIBH2B probe input signals:
| Diagnostic Item | Description |
| Hardware Limit Check | Performs high/low hardware limit checks on probe input signals; exceeding limits generates a fault |
| Software Limit Check | Performs high/low software system limit checks on probe input signals; exceeding limits generates a fault |
| X/Y Probe Pair Monitoring | When either probe in an X and Y probe pair exceeds limits, a probe fault, alarm, or trip condition occurs |
| Position Input Monitoring | Position inputs for thrust wear, differential expansion, eccentricity use DC component for position indication; exceeding limits generates a fault |
2. Common Troubleshooting
| Fault Symptom | Possible Cause | Troubleshooting Suggestions |
| No signal on a channel | Probe failure, wiring error, incorrect jumper configuration | Check probe, wiring, and jumper settings |
| Abnormal signal fluctuation | Probe installation issue, interference, probe damage | Check probe installation, shield grounding, test with replacement probe |
| Frequent alarm triggering | Improper limit settings, mechanical issue | Check limit settings, analyze vibration trends |
| Abnormal BNC output | Buffer circuit issue, excessive load | Check if load exceeds 1500 Ω |
3. Maintenance Recommendations
Periodic Calibration: Calibrate vibration channels according to GE's recommended schedule.
Cleaning and Inspection: Regularly check board cleanliness, remove dust and contaminants.
Connection Check: Verify all connectors are secure and BNC connectors have good contact.
Trend Analysis: Periodically collect vibration data using BNC interfaces for trend analysis.
Spare Parts Management: Maintain a spare TVIBH2B board to reduce downtime in case of failure.
VI. Installation and Configuration
1. Mounting Location
The IS200TVIBH2B board is typically mounted on a terminal board bracket inside the gas turbine control cabinet. During installation, pay attention to:
Ensure the board is firmly mounted to avoid vibration effects.
Leave sufficient space for connecting cables and BNC connectors.
Avoid mounting the board near heat sources.
2. Probe Wiring
Each probe connects to the terminal blocks using three wires:
Correctly connect power, signal, and common according to the probe manual.
Use shielded cables and ensure proper shield grounding.
Avoid running probe cables parallel to power cables.
3. Jumper Configuration
Set JP1A-JP8A according to probe type:
Determine the type of each probe (proximity, velocity, accelerometer, seismic).
Consult the board layout diagram to find the corresponding jumper locations.
Place the jumpers in the correct position (S, V, P, or A).
Record the configuration information for future maintenance.
4. System Connection
Simplex System Connection:
TVIB1 JR1 → VVIB J3
TVIB2 JR1 → VVIB J4
TMR System Connection:
TVIB JR1 → R controller VVIB
TVIB JS1 → S controller VVIB
TVIB JT1 → T controller VVIB
Bently Nevada System Connection:
5. Power-On Verification
After installation, perform the following checks:
Confirm all connections are correct and secure.
After power-up, verify probe supply voltage is normal (-23 to -26 V dc).
Check each channel signal via the controller monitoring software.
Verify buffered outputs using portable equipment connected to BNC interfaces.
