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Maximum number of GPIB connectors in star connect

Question asked by ATE_Eng_2000 on Apr 9, 2009
The requirements for GPIB connections list the maximum number of instruments on a 488 bus to 15. 
1.  Theoretically, could 14 instruments be connected via GPIB cables/connectors in a star configuration to a GPIB controller? 
2.  Is there a recommended maximum number of connectors at a single connection point in a star configuration?  If so, why?

A recent discussion (2/15/09) discussed the possibility of "ringing on the Data Valid line" that could be fixed by "adding a GPIB cable in a loop at the problem instrument".  This problem "seems to affect newer instruments more than older instruments".  "dnt" says that the extra GPIB cable loop adds extra impedance, which helps to dampen the ringing.
3.  Is the observed "ringing" problem due to too many connectors being connected in a star configuration? 
4.  If so should the 488 connection requirements be changed, or should the instruments be designed better to prevent the problem?

Good ole' Wikipedia lists the maximum number stacked GPIB connectors to 4: "Mechanical considerations limit the number of stacked connectors to four or less."
5.  I assume this is because too many connectors put too much weight at the connection point, correct?

Thanks.  

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