The IS200SHRAH2A is a high-performance, compact HART (Highway Addressable Remote Transducer) enabled analog input/output terminal board within the General Electric (GE) Mark VIe control system. As a member of the SHRA family, the IS200SHRAH2A is specifically designed to connect to the PHRA I/O pack (model IS220PHRA), providing 10 channels of 4-20 mA analog input and 2 channels of 4-20 mA analog output for industrial process control. It simultaneously supports transparent bidirectional transmission of the HART communication protocol. Featuring a convenient pluggable terminal design that greatly simplifies on-site wiring and maintenance work, this board is an ideal choice for process signal acquisition and control loops in petrochemical, power generation, and metallurgy industries.
The core advantage of the IS200SHRAH2A lies in its HART pass-through capability. It allows HART commands originating from the control system (via the PHRA I/O pack) to pass unimpeded to HART-enabled smart field transmitters, and returns the HART response signals from the field devices back to the control system. This enables remote parameter configuration, diagnostic data retrieval, and device status monitoring without affecting the normal transmission of the 4-20 mA analog signal. This feature allows users to fully utilize the advanced functionality of intelligent field devices without requiring additional wiring.
System Positioning and Compatibility
Within the Mark VIe control architecture, the IS200SHRAH2A serves as part of the process I/O subsystem, positioned between the controller's Ethernet network and the field devices. Its working mode is as follows: the PHRA I/O pack plugs directly into the D-type connector on the IS200SHRAH2A board and exchanges high-speed data with the controller over Ethernet. One IS200SHRAH2A corresponds to one PHRA I/O pack, forming a compact simplex analog acquisition and output unit.
It is important to note that the IS200SHRAH2A is only compatible with the PHRA I/O pack (all versions of IS220PHRA) and is not compatible with the YHRA I/O pack. The board provides a simplex configuration only and does not support Triple Modular Redundant (TMR) applications, making it suitable for control loops that are cost-sensitive or have less stringent redundancy requirements.
Core Functional Features
1. Rich Analog Input and Output Channels
The IS200SHRAH2A provides 10 analog inputs and 2 analog outputs, totaling 12 channels. Of these, 8 inputs can be configured via jumpers for either 4-20 mA current input or ±5 V DC voltage input, accommodating different transmitter interface requirements. An additional 2 inputs can be configured for either 4-20 mA or ±1 mA current input, offering a flexible connection method for special low-current signals. The 2 analog outputs are standard 4-20 mA current outputs, capable of directly driving loads such as actuators, positioners, or recorders.
The board provides a 24 V DC supply for all transmitters, with a maximum of 21 mA per channel. This can directly power two-wire transmitters, simplifying field power distribution design.
2. Transparent HART Communication
The HART protocol is an industrial standard that superimposes frequency signals onto a 4-20 mA analog signal to achieve digital communication. The IS200SHRAH2A supports complete HART signal pass-through: when an input channel is configured for 4-20 mA current mode via jumpers, HART modulated signals can be transmitted bidirectionally through the data link comprising the terminal board, the PHRA I/O pack, and the controller. Asset management systems or handheld HART communicators on the control system can use this path to remotely access field HART devices, reading device identification, configuration parameters, diagnostic information, and multi-variable data. This significantly enhances equipment management efficiency and predictive maintenance capabilities.
Please note that HART communication is only available when the input is set to 4-20 mA mode. If an input is configured for ±5 V DC voltage or ±1 mA current mode, the HART signal will be isolated or filtered out, preventing communication.
3. Pluggable Terminal Design
Unlike the fixed terminals of the SHRAH1A, the IS200SHRAH2A employs a right-angle header that accepts a variety of commercially available standard pluggable 48-pin Euro-block type terminal blocks. This design offers significant convenience: during field wiring, all cables can first be landed on the pluggable terminal block, which can then be inserted onto the board as a single unit for quick installation. When replacing the board, only the terminal block needs to be unplugged, eliminating the need to remove each wire individually, which greatly reduces downtime for maintenance. A grounding point for the I/O cable shield is provided adjacent to the terminal block, effectively suppressing electromagnetic interference.
4. Flexible Jumper Configuration
The IS200SHRAH2A achieves highly flexible channel configuration through onboard jumpers, allowing adaptation to different field signal types without hardware changes. The specific jumper functions are as follows:
Jumper Group | Function | Configuration Options |
JP1A to JP8A | Select input type for channels 1 through 8 | Current input (4-20 mA) or Voltage input (±5 V) |
JP1B to JP8B | Select return connection method for channels 1 through 8 | Return connected to Common or left Open |
JP9A and JP10A | Select input current range for channels 9 and 10 | 4-20 mA or ±1 mA |
JP9B and JP10B | Select return connection method for channels 9 and 10 | Return connected to Common or left Open |
All other configurations, such as range settings, filter parameters, and HART communication enable, are performed by the PHRA I/O pack through the ToolboxST application software, without the need to manipulate the terminal board itself.
5. Onboard Diagnostics and Identification
The IS200SHRAH2A provides a series resistor for each analog output channel. The voltage drop across this resistor indicates the actual output current, allowing the PHRA I/O pack to perform real-time diagnostics. If any one of the analog outputs becomes unhealthy (for example, due to an open circuit, short circuit, or overload), the PHRA will generate a diagnostic alarm.
An onboard read-only ID chip is also integrated, storing the terminal board's serial number, board type, revision number, and the associated JR/JS/JT connector location. The PHRA I/O pack reads this ID chip upon power-up initialization. If a mismatch is detected between the actual board model connected and the configured one, a hardware incompatibility fault will be generated, effectively preventing system abnormalities caused by incorrect board insertion.
6. Wide Transmitter Support
The IS200SHRAH2A supports multiple field transmitter wiring methods, including:
Two-wire transmitters: Powered by the 24 V DC supply from the terminal board; signal and power share a single wire pair.
Three-wire transmitters: Powered by the 24 V DC supply from the terminal board; signal and power share a common return wire.
Four-wire transmitters: Signal and power are completely separated; the transmitter is powered independently or from the onboard supply.
Externally powered transmitters: The transmitter is powered by an external source; only the 4-20 mA signal is connected to the terminal board.
This compatibility allows the IS200SHRAH2A to integrate seamlessly into existing field wiring schemes, protecting the user's existing investment.
Installation and Wiring Highlights
Installation of the IS200SHRAH2A follows these steps: first, assemble the plastic insulator and the terminal board, then secure them to a metal mounting plate (or bracket). Finally, snap the metal plate onto a DIN-rail or bolt it directly inside the cabinet. For wiring, it is recommended to use 18 AWG (approximately 0.8 mm²) shielded twisted-pair cable to effectively suppress electromagnetic interference and ensure signal integrity. The cable shield drain wire should be terminated at the dedicated grounding terminal adjacent to the terminal block to avoid creating ground loops.
Using the pluggable terminal blocks: insert the stripped wire ends into the corresponding holes of the terminal block and tighten the screws. After confirming the connections are secure, align the entire terminal block with the right-angle header on the board and push it into place to complete the electrical connection. During maintenance replacement, simply unplug the terminal block from the old board, install the new board, and plug the terminal block back in. No rewiring is needed, greatly reducing downtime.
Application Scenarios
The IS200SHRAH2A is suitable for various industrial process control applications. Typical applications include:
Acquisition of two-wire or four-wire transmitter signals for process variables such as pressure, temperature, flow, and level.
Output of 4-20 mA control signals to actuators like smart valve positioners and variable speed drives.
Asset management projects requiring remote access to HART instruments for configuration and diagnostics.
Simplex systems with a single controller architecture, such as auxiliary systems, water treatment, and boiler control.
