Todd, The routine looks like this on the Output Console:
HP3458A 24.4 0 1 The 0 pops up after several seconds and the 1 after even more seconds later. No other output after the 1. The temperature reading is OK but no voltage readings. Thanks for the assistance but I likely have a hardware issue. I did the service note 13A test and the unit passed it fine. I will have to do more troubleshooting on my own but I really appreciate the help. Randy Evans. On Sun, Dec 31, 2017 at 6:09 AM, Todd Micallef <[email protected]> wrote: > Randy, > > I put together a quick script for testing your connection. I have emailed > it to you but attached it here for others if needed. It will be easier than > running the other program. > > Todd > > On Sun, Dec 31, 2017 at 9:00 AM, Dr. Frank <[email protected]> > wrote: > > > Randy, > > > > I doubt, that your hp unit is defective, as it might work under certain > > circumstances, and also the FW version 8.2 vs. 9.2 will not make any > > difference, as only a few pair of bytes are different. All versions of > the > > A5 board are designed to be completely interchangeable over all versions > of > > 3458A instruments. > > > > I have another theory, which deals with the hardware version difference > > between the agilent and the hp unit. > > > > Your agilent unit might already have the 66547, full SMD board for A5, > > whereas the hp will for sure have one of the old 66505/515, through- hole > > boards, Rev A, B, or C. Illya has all of them pictured in his first 3458A > > repair blog. > > > > All the old versions (A, B, C) have GPIB bus transceivers, TI 75ALS160 > > for the data bus, and NS 75161 for the handshake signals. > > The new SMD board has TI 75ALS160 / TI 75ALS161, instead. > > > > So, the handshake bus uses a different logic family for the new board, > and > > therefore, the logic levels / immunity might be slightly different. > > > > My hp3458A has got the REV C A5 board, and it's from 2000. > > Since 2009, I run a similar datalogging program for capturing LTZ1000 > > output versus time, each 4 seconds, on an old PC with WIN98, Turbo > Pascal, > > an XT bus GPIB card from CEC, with the NEC chip. > > > > This program and hardware ran properly for years, (decades), until more > > and more errors during the 24h acquisition runs occured, vaguely > reminding > > me of your trouble. > > The output values were always correct, but frequently, 10sec time-outs > > ocurred, giving zero readings in the datalog. This time-out is obviously > > related to the handshaking mechanism. > > Finally, I found out, that the old ATX PSU was failing, especially its > > input snubber network was gone defect, which probably created big EMC > > spikes. > > After replacing the PSU, all these errors vanished completely. > > > > My conclusion was, that the GPIB bus is susceptible to such EMC > > disturbances, although it's solid TTL logic. > > As obviously the handshake signals were affected only, their higher > > susceptibility to disturbances may be caused by the difference in the > logic > > family of the transceiver IC. The agilent 3458A might be more tolerant to > > that, having the ALS161 version, instead. > > > > So you might also look for EMC problems in your lab, like SMPS, LED > lamps, > > or a defective PC power supply. > > > > Maybe, these Prologix adaptors (clones?) have critical logic levels, > > especially on the handshake bus, or an improper ground. > > You might search for these signal problems directly on the GPIB cable. > > > > Frank > > > > _______________________________________________ > > volt-nuts mailing list -- [email protected] > > To unsubscribe, go to https://www.febo.com/cgi-bin/m > > ailman/listinfo/volt-nuts > > and follow the instructions there. > > > > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/volt-nuts > and follow the instructions there. > _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
