Archived:Differences Between the GPIB-120A and GPIB-120B

Updated May 3, 2018

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Reported In


  • GPIB-120A
  • GPIB-120B

Issue Details

I noticed that GPIB-120A is no longer available through the website, there is only information and pricing for GPIB-120B. What are the differences between the two products and is GPIB-120B a replacement for GPIB-120A?


The principal differences between the GPIB-120A and GPIB-120B are listed below:


  • Uses optical isolators to isolate the two GPIB buses from one another, but uses electric isolators to isolate the buses from the power supply and backplane of the unit
  • Has break down voltage isolation of 1600V
  • Only isolates one port from the ground


  • Uses electrical isolators to isolate the buses from one another and from the backplane and power supply of the unit
  • Has break down voltage isolation of 2500V
  • Has each port fully isolated from ground


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