34401A DMMs新旧有什么区别

我正在用Agilent 34401A设备替换旧的HP 34401A数字万用表。
较旧的HP设备可以正常工作，但Agilent设备正在测试软件中执行操作。
两个单元之间唯一明显的区别是I / O菜单。
较旧的单元具有HP-IB / 488作为接口，而较新的单元接口显示为GPIB / 488.问题是有什么区别？



     以下为原文

  I am replacing an older HP 34401A DMM with an Agilent 34401A unit.  The older HP unit works but the Agilent unit is causing an execption in the test software.  The only difference that is noticeable between the 2 units is the I/O menu.  The older unit has HP-IB / 488 as the interface while the newer unit interface is showing as GPIB / 488.  The question is what is the difference?