The IS200DTURH1A is a Simplex Pulse Rate Input Terminal Board designed by General Electric (GE) for its Mark VI™ Control System. This board is the standard version within the DTUR series, featuring a compact design specifically for DIN-rail mounting. It provides the control system with 4 channels for processing signals from passive pulse rate transducers (magnetic pickups), primarily used for speed and flow measurement.
The IS200DTURH1A board works in conjunction with the VTUR processor board, connecting via one 37-pin cable and one 15-pin cable to acquire the 4 pulse signals. These cables are identical to those used on the larger TTUR terminal board, facilitating spare parts management. Each VTUR processor board can only accommodate one DTUR board.
Key features of the IS200DTURH1A include:
Compact Design: Suitable for DIN-rail mounting, can be stacked vertically to save cabinet space.
4 Pulse Inputs: Can interface with 4 passive magnetic speed pickups for speed and flow measurement.
Coordination with VTUR: Connects to the VTUR processor board via JR1 and JR5 connectors, with the JR5 cable carrying all signals.
High-Precision Measurement: Pulse rate accuracy of 0.05% of reading, with minimum detectable signal of 27 mV pk at 2 Hz, corresponding to 2 RPM speed.
Wide Frequency Range: Supports a pulse rate range of 2 Hz to 20 kHz.
Signal Conditioning: Features onboard signal conditioning identical to the TTUR board.
ID Chip Identification: Two onboard ID chips identify the connectors and terminal board to the VTUR for system diagnostic purposes.
Jumperless Design: The board has no configurable jumpers; all functions are fixed, simplifying field maintenance.
The board operates within a temperature range of -30 to 65°C, suitable for industrial control cabinet environments. It is important to note that the DTUR only supports simplex systems and is not compatible with the Mark VIe system.
II. Main Functions
The primary functions of the IS200DTURH1A include, but are not limited to, the following:
1. Pulse Signal Acquisition
The IS200DTURH1A board provides 4 passive pulse rate sensor input channels for acquiring signals from magnetic speed pickups. These signals can originate from devices such as turbine speed sensors or flow meters. Speed or flow rate is calculated by measuring the pulse frequency.
2. Signal Conditioning
The board features onboard signal conditioning circuits identical to those on the TTUR, including filtering and amplification, ensuring pulse signal integrity and noise immunity. The conditioned signals are transmitted to the VTUR processor board via the JR5 connector for processing.
3. High-Precision Measurement
Pulse frequency circuits within the VTUR processor board process the input signals, achieving high-precision frequency measurement. The pulse rate accuracy is 0.05% of reading, ensuring accurate speed and flow measurements.
4. Low-Speed Detection Capability
The input circuit sensitivity is 27 mV pk (at 2 Hz), capable of detecting speeds as low as 2 RPM. This feature makes the IS200DTURH1A suitable for applications requiring monitoring of low-speed rotation or startup processes.
5. ID Chip Identification
The board features two read-only ID chips corresponding to the JR1 and JR5 connectors. These chips store the board's serial number, type, revision number, and connector location information. The VTUR reads this information during initialization. If a mismatch is encountered, a hardware incompatibility fault is generated, preventing system problems caused by incorrect configuration.
6. Support for Passive Probes
The IS200DTURH1A is specifically designed for passive magnetic speed pickups, requiring no external power, simplifying field wiring. Probes connect to the board's terminal block via shielded twisted pair wiring.
III. System Applications
1. Application in Mark VI Control System
The IS200DTURH1A is a compact terminal board for speed and flow measurement within the Mark VI control system. Working with the VTUR processor board, it forms a complete pulse signal acquisition subsystem.
In the system, the IS200DTURH1A plays the following roles:
Speed Measurement: Acquires speed signals from rotating equipment such as steam turbines and gas turbines, providing speed feedback for control and protection systems.
Flow Measurement: Receives pulse signals from devices like turbine flow meters to calculate fluid flow rate.
Speed Monitoring: Monitors the operating speed of auxiliary equipment such as pumps and fans.
2. Differences from TTUR
The main differences between DTUR and TTUR are functional scope and size:
| Feature | DTUR | TTUR |
| Size | Compact | Standard size |
| Mounting Method | DIN-rail | Panel mount |
| Input Channels | 4 pulse inputs | 12 pulse inputs + voltage inputs, etc. |
| Generator/Bus Voltage Inputs | Not supported | Supported |
| Shaft Voltage/Current Inputs | Not supported | Supported |
| Maximum per VTUR | 1 board | 1 board |
| Connection Cables | JR1 + JR5 | Multiple cables |
DTUR focuses on pulse rate input, suitable for applications requiring only speed or flow measurement, providing core functionality in a smaller footprint.
3. Typical Application Scenarios
Steam Turbine Speed Monitoring: Acquires steam turbine speed signals for overspeed protection and speed control.
Gas Turbine Speed Measurement: Monitors gas turbine speed, providing feedback for the control system.
Flow Metering: Receives signals from turbine flow meters to calculate liquid or gas flow.
Pump Speed Monitoring: Monitors the operating speed of industrial pumps for process control and equipment protection.
Fan Speed Measurement: Acquires fan speed signals for ventilation system control.
IV. Detailed Interface Description
1. Terminal Block
The IS200DTURH1A features a permanently mounted 36-terminal terminal block for connecting the 4 passive pulse rate sensors. Each sensor uses shielded twisted pair wiring, occupying two terminals (signal high and signal low). Terminals 35 and 36 are dedicated for the SCOM (shield common) connection.
2. Grounding Requirements
Important: SCOM (terminals 35 and 36) must be connected to ground with the shortest possible wire to ensure shielding effectiveness and signal integrity. The board has no dedicated shield terminal strip, making this ground connection particularly critical.
3. Connectors
The board connects to the VTUR processor board via two connectors:
Note: Only the JR5 cable carries signals to VTUR.
4. Recommended Wire Gauge
Use #18 AWG shielded twisted pair wiring to connect magnetic speed pickups, reducing electromagnetic interference and ensuring signal quality.
V. Diagnostics and Maintenance
1. Diagnostic Functions
The IS200DTURH1A provides the following diagnostic functions via the VTUR:
| Diagnostic Item | Description |
| ID Chip Verification | VTUR reads the ID chips on the JR1 and JR5 connectors and compares them with the configuration. A mismatch generates a hardware incompatibility fault. |
2. Common Troubleshooting
| Fault Symptom | Possible Cause | Troubleshooting Suggestions |
| No pulse signal on a channel | Probe failure, wiring error, disconnected cable | Check probe and wiring, check probe output with an oscilloscope |
| Inaccurate pulse frequency | Incorrect probe mounting gap, interference | Check probe mounting gap, check shield grounding |
| Reading fluctuating or unstable | Poor shield grounding, electromagnetic interference | Check SCOM grounding, check cable routing |
| Hardware incompatibility fault | ID chip information mismatch | Verify correct board model, contact GE technical support |
3. Maintenance Recommendations
Periodic Inspection: Check terminal blocks for looseness and wires for oxidation.
Cleaning: Regularly clean the board to prevent dust accumulation affecting heat dissipation and insulation.
ESD Protection: Wear a grounding strap when handling the board and store it in anti-static bags.
Spare Parts Management: Maintain a spare IS200DTURH1A board to reduce downtime in case of failure.
VI. Installation and Configuration
1. Installation Steps
Mount DIN Rail Holder: Install the plastic holder onto the DIN rail.
Install Board: Slide the DTUR board into the holder until it snaps into place.
Connect Probe Wires: Connect the shielded twisted pair wires from the magnetic speed pickups to the terminal block. Each probe uses two terminals.
Ground Connection: Connect terminals 35 and 36 (SCOM) to ground using the shortest possible wire.
Connect Cables:
Verify Installation: Confirm all connections are secure.
2. Multi-Board Stacking
When multiple DTUR boards are required, they can be stacked vertically on the DIN rail. Each board connects independently to its own VTUR processor board (each VTUR can only support one DTUR). When stacking, ensure adequate spacing between boards for heat dissipation and wiring access.
3. Configuration Method
The IS200DTURH1A board has no jumpers or hardware settings. All configuration is done via software on the VTUR processor board.
