WESTINGHOUSE 7379A21G01 Westinghouse Q-Line QAV Card

Descripution

The 7379A21G01 is a Westinghouse Q-Line QAV (Analog Input) control card used in Ovation and WDPF distributed control systems. It converts analog field signals into digital data for system processing.

Each QAV card contains six individually isolated voltage-to-frequency converter circuits (channels). The output of each input circuit is processed by a common microcomputer and the resulting digital data is multiplexed to the Distributed Input/Output Bus (DIOB) as a 13-bit word.

Figure shows a typical control system configuration using QAV cards. The QTB card is necessary for applications where large variations of power line frequency exist to obtain a high normal mode rejection. Up to 30 QAV cards (180 channels) can be used with one DIOB controller.

Cards equipped with the thermocouple temperature compensation feature use channel 6 for the on-card temperature sensor. The channel is read every time the card performs an auto-calibration cycle. The on-card temperature sensor eliminates the need for external sensor boards, and ensures field temperature accuracy.

The QAV card uses an electrical isolation circuit (transformer) to separate the analog input from the digital counting circuits. The isolation circuit provides power for each analog input channel in addition to precise timing from a stable frequency which is generated on the digital side of the QAV card circuits.

Each analog input circuit contains circuitry for signal conditioning, biasing, auto-zero and gain correction, open thermocouple detection (not available on G04 and G05 QAV cards) and a clocked voltage-to-frequency converter.

Offset and gain correction factors are calculated on a periodic basis by the QAV card microcomputer. The frequency of the offset and gain calibration cycle is determined by a constant which has been programmed into the memory of the system controller.

Two known potentials on the analog section of the QAV card are used as standards for offset and gain calibrations. One standard is a 0 VDC (shorted input), which is used to determine the offset correction factor. The second calibrating potential (gain) is derived from a separate, stable voltage reference which is set approximately −150% of the maximum expected analog input value. The gain correction factor is compared to a 16-bit calibration constant which is programmed into the memory of the system controller at the time of factory card calibration. The calibration constant is necessary because the QAV card has no mechanical adjusting devices (such as potentiometers, and so on). This method yields a trimmer (or pot) -less calibrating method.

QAV Typical Control System Using QAV Cards

Features

Each QAV card has the following features:

• IEEE surge withstand capability

• Auto zero, auto gain correction

• Electrical isolation on all channels

• On-card digital memory (buffer)

• Open thermocouple detection (This feature is not available on G04 and G05 QAV cards.)

• Common mode rejection

• Normal mode rejection

• Automatic reasonability test (shorted input)

• Auto-conversion check

• Jumper selectable 50/60 Hz operation

• On-card thermocouple temperature compensation (Available on QAV cards at level 6 QAV)

The QAV card is designed to be mounted in a standard Q-line card cage. Connection to the control system is made by a 34-pin rear-edge backplane connector which interfaces the UIOB or DIOB and a 56-pin front-edge connector, which connects to field terminals.

FAQ

Q1. How does the 7379A21G01 Q-Line QAV Card enhance operational efficiency within Emerson automation and control system ecosystems?

The 7379A21G01 is designed to support reliable signal processing and system communication within Emerson control architectures. Its robust engineering helps improve data integrity, system responsiveness, and overall operational continuity in industrial environments.

Q2. Why is the 7379A21G01 considered a valuable component for maintaining high-availability process control infrastructures?

The 7379A21G01 is manufactured to meet the demands of mission-critical applications where uninterrupted system performance is essential. Its dependable design helps minimize downtime and supports long-term operational stability across complex automation platforms.

Q3. What technical criteria should engineers evaluate before integrating the 7379A21G01 into an existing Q-Line control framework?

When deploying the 7379A21G01, engineers should assess system compatibility, interface requirements, communication pathways, cabinet configuration, and environmental operating conditions. Proper integration ensures optimal performance and seamless interoperability with existing control assets.

Q4. How can the 7379A21G01 contribute to lifecycle optimization and maintenance strategy improvement?

The 7379A21G01 is supplied as a brand-new factory-sealed original component, helping maintain system authenticity and reliability. Its quality construction can reduce maintenance frequency, support predictable asset management, and extend the operational lifespan of automation equipment.

Please contact us for more related Information

Sales manager：Miya zheng；Email:sales@amikon.cn；WhatsApp:86-18020776792；WeChat:86-18020776792

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