DS3800HNMB1B - Pulse Rate Board

SPECIFICATIONS

Part Number: DS3800HNMB1B
Manufacturer: General Electric
Series: Mark IV
Product type: Null Modem Communication Card
Availability: In Stock
Country of Manufacture: United States (USA)

Functional Description

DS3800HNMB1B is a Null Modem Communication Card designed and developed by GE. It is a part of Mark IV control system. This card facilitates serial communication between control modules by providing a null modem interface, which allows direct device-to-device data exchange without the need for modems or intermediary devices.

Features

• Designed to facilitate communication between two DTE (Data Terminal Equipment) devices by internally crossing transmit and receive lines. This eliminates the need for a modem or other intermediate device.
• Specifically built for use within GE’s Mark IV control system, which is widely used for the control and monitoring of gas and steam turbines. The card is optimized for compatibility and performance within this legacy control environment.
• In the GE Mark IV control system, critical sensors such as exhaust thermocouples are distributed across the R, S, and T control sections typically with 4 assigned to R, 5 to S, and 4 to T allowing each section to independently monitor turbine conditions. These readings are sent to the coordinating module C, which calculates the median value of all thirteen thermocouples and returns it to R, S, and T for unified control. Under normal conditions, turbine operation is based on this median value to ensure stable performance. In case of a fault, each section retains the capability to assess conditions independently and limit fuel flow accordingly, enhancing system reliability and safety.

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FREQUENTLY ASKED QUESTIONS

What is DS3800HNMB1B?
It is a Null Modem Communication Card designed and developed by GE.

How are the exhaust thermocouples typically distributed?
In a common configuration, thirteen exhaust thermocouples are divided as follows: 4 to , 5 to S, and 4 to T. This balanced distribution ensures that no single section holds all the critical data.

What is the role of the C module in this setup?
The C module acts as the coordinator. It receives temperature readings from R, S, and T, calculates the median value, and then sends this value back to all three sections for consistent control.

Why is the median value used instead of the average?
Using the median value helps minimize the impact of any outlier or faulty sensor reading, providing a more stable and accurate basis for turbine control.