Hooked on HP... Does 16701B work with 16700A/16702A? - Page 1
Forum section: electronics / testgear

author: ZaneKaminski
author_rank: Contributor
timestamp: April 11, 2017, 07:05:40 am
content: I have acquired quite a few 16500/16700 measurement modules which I want to put into my 16702A system, so I need the 16701A/B expansion frame. The 16701B is typically much cheaper than the 16701A. Why's that? Is the 16701B compatible with the earlier 16700A mainframes?Is there anything else I should watch out for when acquiring the expansion frame? What about the cable which connects the two? It seems pricey and rare. Is there a cheap substitute?Zane

author: helius
author_rank: Super Contributor
timestamp: April 11, 2017, 07:26:37 am
content: The 16701B is compatible with the 16700A, 16702A, 16700B, and 16702B mainframes. It appears identical to the 16701A.The cable looks like an ordinary shielded 100-pin twisted spectrastrip. I don't think there is any magic to it.

author: ZaneKaminski
author_rank: Contributor
timestamp: April 11, 2017, 08:05:55 am
content: Okay, thanks. What are the differences between the -701A and -701?Edit: Or when you say it "appears identical," do you actually mean that the units are physically very similar? At first I thought you meant that they present an identical interface to the 16700-series host.

author: MarkL
author_rank: Unknown
timestamp: April 11, 2017, 01:52:25 pm
content: Quote from: ZaneKaminski on April 11, 2017, 07:05:40 amThere are two cables available (at least that I've seen): 16701-61602 which is 12", and 16701-61604 which is 36". The 36" one is more rare. Occasionally you can find someone selling the expansion chassis with the cable.I wanted to turn my 16701B around so I could easily access the inputs on some 16534A scope cards I have for it, so I decided to make a 60" cable. It cost me around $75 in parts from Digikey. That's not exactly cheap but still better than $200 for the 36" one on ebay.I used flat (non-twisted) 0.025" ribbon since that's what HP/Agilent used for the interconnects inside the chassis to get to the back connector. My cable is not shielded like the real one (no problems so far), and I had to use the latches instead of thumbscrews since that was the only shell I could easily get.If there's interest I can dig up the parts list and some how-to photos.I'll have to defer on chassis differences question; I don't really know.

author: helius
author_rank: Super Contributor
timestamp: April 11, 2017, 07:15:01 pm
content: By "appears identical", I mean that it has the same slots (5 LA modules and 2 emulator cards), and the same cabling (100 pin bus) as the 16701A. The extension chassis are mostly passive, so I don't see why they wouldn't be equivalent in use.

author: gslick
author_rank: Frequent Contributor
timestamp: April 12, 2017, 05:37:06 am
content: As far as I know the main difference is that the early 16701A expansion frames were 2 fan models and the later 16701A expansion frames were 3 fan models, while all 16701B expansion frames were 3 fan models.The 2 fan models have 2 fans on the side and none in the center strut. The 3 fan models have 1 fan on the side and 2 in the center strut.I believe this change was required due to increased cooling requirements of newer analyzer modules, and possibly that is what this document is about, although it doesn't mention the details of the hardware upgrade:http://literature.cdn.keysight.com/litweb/pdf/16715-92007.pdfFrames with the following serial numbers need to be upgraded to operate with 16715A, 16716A, 16717A, 16718A, 16719A, 16740A, 16741A, 16742A, 16750A/B, 16751A/B, 16752A/B, 16753A, 16754A, 16755A, 16756A, or 16760A measurement modules.So while either a 16701A or 16701B expansion mainframe should be good with either a 16700A, 16702A, 16700B, or 16702B mainframe, some early 16701A expansion mainframes may not be supported with all analyzer modules. (Also some 16700A and 16702A mainframes may not be supported with all analyzer modules.) This may really be a case it works at your own risk even if not officially supported.

author: F1GWR
author_rank: Regular Contributor
timestamp: November 29, 2024, 02:11:53 pm
content: Hi Mark,Quote from: MarkL on April 11, 2017, 01:52:25 pmI'd appreciate if you could provide us the reference of the connectors and if the ribbon cable is connected:- straightforward 1-1, 2-2, ..100-100- or reversed 1-100, 2-99, ..100-1- and if there are cross-over(s), any void interconnects(s), and/or impedance compensation resistors/caps?Thanks,Christian

author: MarkL
author_rank: Unknown
timestamp: November 29, 2024, 04:59:52 pm
content: The cable uses the 3M MDR series. Here are the part numbers:Connector: 3M 101A0-6000ECRibbon shell with thumbscrews: 3M 103A0-12R1-00Round cable shell with clips: 3M 103A0-C200-00Cable: 3M 3754/100You want the ribbon shell. When I built my cable years ago, the only shell I could get was the one for round cable and with clips. I had to machine a slot in the back to accommodate the ribbon, and had to remove the jack screws from the chassis to provide clearance for the latches.I now see someone is selling the ribbon shell on ebay. I might go back and replace my modified shell with the correct ribbon one and undo the chassis mod.The cable is straight through, 1-1, 2-2, ... 100-100. No passives or anything weird like on the probe cables.I took some photos while I was building it, below. Of course these connectors were meant to be assembled by a ridiculously priced machine. I did the best I could. The photos are low res but if you need more detail on anything let me know.The 3M MDR series is also used on 100-pin SCSI cables. I don't know if all 100 pins go through, and if they do, if the grounding and twisted pairs are right. But it might be a source for parts instead of buying new.

author: helius
author_rank: Super Contributor
timestamp: November 29, 2024, 07:33:25 pm
content: While there might be some SCSI-derived systems using 100 pins, none of the common, off-the-shelf, standardized peripherals use so many pins. The 32-bit wide SCSI-2 standard was later withdrawn, and the SCSI-3 port with the most pins is SCA-2 with 80 pins from drive to backplane. I have used hundreds of SCSI cables of various different types and never seen one with 100 pins.

author: gslick
author_rank: Frequent Contributor
timestamp: November 29, 2024, 08:08:27 pm
content: If someone in the US needed one of these cables, you probably couldn't find a less expensive solution than this one currently:HP Agilent 3M 16701-61602 Logic Analyzer Expansion Cable (11" Long)https://www.ebay.com/itm/114877229724US $16.00Outside of the US, I imagine shipping would be an issue.

author: F1GWR
author_rank: Regular Contributor
timestamp: September 13, 2025, 10:25:06 am
content: Thanks! Very nice job.

author: F1GWR
author_rank: Regular Contributor
timestamp: September 13, 2025, 10:27:35 am
content: Hi,Bought it but DHL still sits on the package in my country since 2 weeks.