What Do the Isolation Specifications Mean in the GPIB-120A User Manual?Hardware: GPIB>>Support Products>>GPIB-120A
Problem: The GPIB-120A User Manual lists two specifications for isolation in the specifications section of the manual. One specification is called "operating", and the other is "breakdown". What is meant by these two terms in this context? Solution: To assure that the GPIB-120A is not physically damaged, do not exceed the "operating" isolation voltage, 60V. The "breakdown" isolation voltage, 1600V, is the voltage at which the device will no longer electrically isolate the two GPIB systems. Some customers use this device to serve as something like a circuit breaker to make sure that if a voltage surge is experienced, it will not be passed through to the computer side of the GPIB system. In this sense, the breakdown voltage is the critical specification. Other times, a high common mode voltage is present between the two GPIB systems and the customer wishes to isolate them from each other. In this case, the operating isolation voltage is the relevant specification. If the common mode voltage exceeds 60V, a better solution is to use the GPIB-140A fiber optic extender. The GPIB-120A contains the isolation hardware on one physical unit. The GPIB-140A solution consists of two GPIB-140A units connected by a fiber optic cable. Each GPIB-140A can be referenced to a different voltage. (The difference in their voltages makes up the high common mode voltage.) The unit transfers the GPIB data into a fiber optic signal, which does not consist of current or voltage, so it can be safely passed to the other GPIB-140A unit. Related Links: User Manuals: GPIB-120A User Manual User Manuals: GPIB-140A User Manual Attachments:
Report Date: 10/17/2002 Last Updated: 11/20/2002 Document ID: 2QGHKGBH |
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