The GE IS200TBTCH1CCB Thermocouple Input Terminal Board is a specialized temperature measurement terminal board used within GE Industrial Control Systems. As a member of the TBTC board family, the IS200TBTCH1CCB Thermocouple Input Terminal Board accepts 24 thermocouple inputs and provides the field-side termination, cold junction compensation, noise suppression, and signal conditioning required for accurate temperature measurement in Mark VIe control architectures. The board supports Type E, J, K, S, and T thermocouples, and when used with the PTCCH2 I/O pack it additionally supports Type B, N, and R thermocouples, allowing the board to be matched to a wide range of industrial temperature sensors.
The IS200TBTCH1CCB Thermocouple Input Terminal Board is identified by the GE part numbering convention used throughout the Industrial Control Systems product line. The "IS200" prefix identifies the board as a GE Industrial Control Systems product, with "200" specifically indicating that the board is a base-level assembly. The "TBTC" acronym identifies the board's functional designation as a Thermocouple Input Terminal Board. The "H1" designation identifies the hardware group, while the "CCB" suffix identifies the artwork and functional revision combination, with the C revision providing the simplex configuration with two DC-type connectors. All digits are important when ordering or replacing any board, as boards of different revision levels may not contain identical hardware, and GE ensures backward compatibility of replacement boards while noting that different revision levels may not contain identical components.
The IS200TBTCH1CCB Thermocouple Input Terminal Board is available in two general configurations within the family: the TBTC_1C version for simplex applications, which has two DC-type connectors and provides capacity for 24 thermocouple inputs with two I/O packs, and the TBTC_1B version for simplex and TMR applications, which has six DC-type connectors and provides capacity for 24 thermocouple inputs in simplex with two I/O packs connected to JRA and JTB, or 12 thermocouple inputs in TMR configurations. The IS200TBTCH1CCB Thermocouple Input Terminal Board is the C revision of the H1 board, providing the simplex configuration that is widely used in Mark VIe control systems.
This product introduction provides detailed technical information, functional descriptions, connector assignments, configuration guidance, and comprehensive specifications for the GE IS200TBTCH1CCB Thermocouple Input Terminal Board, serving as an essential reference for control system engineers, maintenance technicians, and system integrators working with GE industrial control equipment.
Functional Architecture and Signal Processing
The IS200TBTCH1CCB Thermocouple Input Terminal Board is built around a robust thermocouple measurement architecture that supports 24 thermocouple inputs, each with noise suppression, cold junction compensation, and hardware limit checking. The board performs several distinct functions that ensure accurate and reliable temperature measurement in electrically noisy industrial environments.
The 24 thermocouple inputs of the IS200TBTCH1CCB Thermocouple Input Terminal Board are wired to two barrier-type terminal blocks mounted on the terminal board. Each block has 24 terminals accepting up to #12 AWG wires, and a shield terminal strip attached to chassis ground is located on the left side of each terminal block to ensure proper shielding and grounding of the thermocouple cables. The terminal blocks can be unplugged from the board for maintenance, simplifying field wiring and board replacement. The thermocouples can be either grounded or ungrounded, providing flexibility for different installation requirements.
The IS200TBTCH1CCB Thermocouple Input Terminal Board accepts Type E, J, K, S, and T thermocouple inputs, and when connected to the PTCCH2 I/O pack it additionally accepts Type B, N, and R thermocouples. The input span is −8 mV to +45 mV when the board is connected to the PTCCH1 or VTCCH1, and −20 mV to +95 mV when connected to the PTCCH2 or VTCCH2. The board also accepts millivolt inputs, allowing it to be used for low-level voltage measurement applications beyond thermocouple temperature measurement.
Cold junction compensation is provided by reference junction temperature measurement at two locations on each H1C terminal board, and the cold junction accuracy is 1.1 °C (2 °F). Because a 1 °F error in the cold junction compensation will cause a 1 °F error in the thermocouple reading, the cold junction accuracy is a critical factor in the overall measurement accuracy of the board. The cold junction signals go into signal space and are available for monitoring, and normally the average of the two is used. Acceptable limits are configured, and if a cold junction goes outside the limit, a logic signal is set.
Thermocouple Ranges and Limits
The IS200TBTCH1CCB Thermocouple Input Terminal Board supports full-scale input ranges for each thermocouple type, and the input voltages for different thermocouple types versus the minimum and maximum temperature ranges are defined in the technical documentation. Cold junction temperature ranges are assumed to be from −30 to 65 °C (−22 to 149 °F).
For the TBTC_1B and TBTC_1C boards, Type E thermocouples span from −51 °C at −7.174 mV to 593 °C at 44.547 mV, Type J thermocouples span from −51 °C at −6.132 mV to 760 °C at 42.922 mV, Type K thermocouples span from −51 °C at −4.779 mV to 1093 °C at 44.856 mV, Type S thermocouples span from −17.78 °C at −0.524 mV to 1760 °C at 18.612 mV, and Type T thermocouples span from −51 °C at −4.764 mV to 399 °C at 20.801 mV. These ranges cover the typical industrial temperature measurement requirements for each thermocouple type.
For the TBTC with PTCCH2, the additional Type B, N, and R thermocouples are supported, extending the measurement capability to higher temperatures and specialized applications. Type B thermocouples span from 0 °C at −0.0114 mV to 1800 °C at 13.593 mV, Type N thermocouples span from −51 °C at −3.195 mV to 1250 °C at 45.694 mV, and Type R thermocouples span from −17.78 °C at −0.512 mV to 1700 °C at 20.220 mV.
Cold Junction Compensation
The cold junction compensation function of the IS200TBTCH1CCB Thermocouple Input Terminal Board is critical for accurate thermocouple measurement, because thermocouples measure the temperature difference between the hot junction and the cold junction, and the cold junction temperature must be known to calculate the hot junction temperature. The board measures the reference junction temperature at two locations on each H1C terminal board, and the TMR H1B board has six cold junction references, of which only three are available with the I/O packs.
Hard-coded limits are set at −40 to 85 °C (−40 to 185 °F), and if a cold junction goes outside this range it is regarded as bad. Most cold junction failures are open or short circuit, and if the cold junction is declared bad, the backup value is used. This backup value can be derived from cold junction readings on other terminal boards or can be the configured default value, ensuring that the temperature measurement continues even if one cold junction sensor fails.
Simplex and TMR Configurations
The IS200TBTCH1CCB Thermocouple Input Terminal Board supports simplex configurations, using two I/O packs plugged into the board to obtain 24 thermocouple inputs. In the Mark VIe system, the board works with the PTCC I/O pack and supports simplex, dual, and TMR applications, with the board providing the field-side termination for the thermocouple signals and the I/O pack providing the analog-to-digital conversion and processing.
The board family also includes the TBTC_1B version for TMR applications, in which the thermocouple signals fan out to three J-connectors and the Mark VIe control systems accommodate 12 inputs. The IS200TBTCH1CCB Thermocouple Input Terminal Board is the simplex version with two DC-type connectors, providing 24 thermocouple inputs with two I/O packs, which is the appropriate configuration for simplex applications where redundancy is not required.
Diagnostics and Fault Detection
The IS200TBTCH1CCB Thermocouple Input Terminal Board provides comprehensive diagnostic capabilities that assist with system verification and fault isolation. Each thermocouple type has hardware limit checking based on preset, non-configurable high and low levels set near the ends of the operating range. If this limit is exceeded, a logic signal is set and the input is no longer scanned. If any one of the input hardware limits is set, it creates a composite diagnostic alarm.
Each terminal board connector has its own ID device that is interrogated by the I/O board. The board ID is coded into a read-only chip containing the terminal board serial number, board type, revision number, and the J connector location. If a mismatch is encountered, a hardware incompatibility fault is created, preventing the system from operating with incorrect or mismatched hardware.
When operating with the I/O processor, a very small current is injected into each thermocouple path. This is done to detect open circuits and is of a polarity to create a low temperature reading should a thermocouple open. This open-circuit detection feature ensures that a failed thermocouple is detected and reported, rather than causing an incorrect temperature reading that could lead to an inappropriate control action.
The diagnostics also monitor readings from all thermocouples, cold junctions, calibration voltages, and calibration zero readings, providing comprehensive coverage of the measurement chain and ensuring that any fault in the thermocouple, the wiring, or the board is detected and reported.
Configuration
The IS200TBTCH1CCB Thermocouple Input Terminal Board has no jumpers or hardware settings on the board. All configuration is performed through the system software and the I/O pack, simplifying installation and reducing the potential for configuration errors. The board's thermocouple type support and input span are determined by the I/O pack to which it is connected, with the PTCCH1 supporting E, J, K, S, and T thermocouples and the PTCCH2 supporting E, J, K, S, T, B, N, and R thermocouples, so the correct I/O pack must be selected for the application.
Application Suitability and System Integration
The IS200TBTCH1CCB Thermocouple Input Terminal Board is a versatile temperature measurement interface that can be used in a wide variety of GE Industrial Control System applications. Its 24 thermocouple inputs, supporting Type E, J, K, S, and T thermocouples with the PTCCH1 and additionally Type B, N, and R thermocouples with the PTCCH2, allow the board to interface with thermocouples used in gas turbine exhaust temperature measurement, steam turbine metal temperature monitoring, boiler tube temperature measurement, and many other industrial temperature measurement applications.
In Mark VIe control systems, the IS200TBTCH1CCB Thermocouple Input Terminal Board works with the PTCC I/O pack, with two PTCC I/O packs plugging into the board at JRA and JTB for a total of 24 inputs in the simplex configuration. The board's unpluggable terminal blocks and clearly labeled connectors simplify installation, verification, and maintenance, and the comprehensive diagnostics, including hardware limit checking, open-circuit detection, and cold junction monitoring, ensure that thermocouple faults are detected and reported.
The board's support for both grounded and ungrounded thermocouples provides flexibility for different installation requirements, and the noise suppression circuitry ensures accurate measurement even in electrically noisy industrial environments. The cold junction compensation, with two reference junctions per H1C board and a backup value strategy for cold junction failures, ensures that the temperature measurement remains accurate and reliable even if one cold junction sensor fails.
Maintenance and Lifecycle
The IS200TBTCH1CCB Thermocouple Input Terminal Board is designed for long service life with minimal maintenance. The board contains no moving parts, and its robust construction ensures high reliability in continuous industrial operation. Routine maintenance consists of periodic visual inspection of the board, terminal blocks, and wiring, verification that the cold junction references are within specification, and confirmation that the shield terminals are properly connected.
The board's diagnostic features, including the hardware limit checking, the open-circuit detection, the cold junction monitoring, and the onboard ID chip, simplify troubleshooting and ensure that the correct board is installed in each location. If a thermocouple opens, the injected current creates a low temperature reading, allowing the open circuit to be detected. If a cold junction goes outside the hard-coded limits, the cold junction is declared bad and the backup value is used, allowing the temperature measurement to continue.
If the board requires replacement, the process is straightforward. After de-energizing the associated equipment and verifying that no power exists, the pluggable terminal blocks should be labeled and removed, and the board should be removed from its mounting. The replacement board should be installed in the same position, and the terminal blocks reconnected as labeled before returning the system to service.
GE Industrial Control Systems ensures compatibility of its replacement boards, even though boards of different revision levels may not contain identical hardware. When ordering a replacement IS200TBTCH1CCB Thermocouple Input Terminal Board, provide the complete part number and description, the drive or system serial number, and the Material List (ML) number. The factory may substitute later versions based on availability and design enhancements, but backward compatibility of replacement boards is guaranteed.
Conclusion
The GE IS200TBTCH1CCB Thermocouple Input Terminal Board is a reliable, robust, and versatile temperature measurement interface for GE Industrial Control Systems. Its 24 thermocouple inputs, supporting Type E, J, K, S, T, B, N, and R thermocouples depending on the I/O pack, its cold junction compensation, its noise suppression, and its comprehensive diagnostics provide the flexibility and accuracy required for a wide range of industrial temperature measurement applications.
With its unpluggable terminal blocks, clearly labeled connectors, comprehensive diagnostics, and compatibility with the Mark VIe PTCC I/O pack, the IS200TBTCH1CCB Thermocouple Input Terminal Board is designed for easy installation, verification, and maintenance. Backed by GE's quality manufacturing, global support network, and commitment to backward compatibility, the IS200TBTCH1CCB Thermocouple Input Terminal Board continues to deliver the performance, durability, and reliability that industrial users expect from GE. Whether used in a new installation or as a replacement for an existing board, the IS200TBTCH1CCB Thermocouple Input Terminal Board provides the thermocouple input functionality required for reliable and efficient control system operation.
