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I'm designing a device that involves the 24-pin GPIB / IEEE-488 connector interface. I’m trying to find the ideal panel-mount female receptacle, but I'm not fully confident I'm even sure what I'm looking for because the socket puzzles me.

I see a lot of receptacles of this and similar kinds, that feature these metallic loops on the sides that I believe are called spring-locks. What are they for?

I failed to find any assembly guides or example images where I'd see those loops in action.

Here's a typical example:

gpib

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    \$\begingroup\$ Readers over a certain age will instantly recognise that as a Centronics printer connector. :-) \$\endgroup\$
    – Steve Melnikoff
    Apr 27, 2018 at 21:31
  • \$\begingroup\$ @SteveMelnikoff - Though certainly they were in use prior to that printer. I can recall them (in smaller sizes) on some instruments in the mid 70s. \$\endgroup\$
    – Hot Licks
    Apr 27, 2018 at 23:15
  • \$\begingroup\$ Oh I've never even seen any of these in real life applications. I got the impression that they were popular in testing equipment and such, so they were more common in certain industries perhaps. I just had a principle in mind that needed to exist for my project, and through research found the stackable IEEE-488 connector that happens to do exactly what I need. Since I'm building a thing for my own use, I don't care if it's unbelievably retro. But I suspect that no consumer would want to see connectors that large anywhere anymore, ever. \$\endgroup\$
    – user158589
    Apr 28, 2018 at 8:59

2 Answers 2

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The mating half of that connector is designed so that the loops can clip into place and thus you have a connector pair that is more resilient to vibration and general movement i.e. the two halves are held together this way without relying on electrical contact pressure.

enter image description here

enter image description here

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  • \$\begingroup\$ Oh I see, that makes sense. I have sockets with the loops, but the GPIB cord I have doesn't have anything for those loops to interact with, so no wonder it didn't make any obvious sense. These parts fit but are by a different manufacturer. If I attach the cord to its own other end (infinite pointless loop), what they have for securing the connection is kind of stacking screws. \$\endgroup\$
    – user158589
    Apr 27, 2018 at 13:34
  • \$\begingroup\$ @user158589 The hole on the side will likely be spaced for those screws, you can put threaded stand-offs there if you want to use those screws to secure the plug. \$\endgroup\$
    – ratchet freak
    Apr 27, 2018 at 13:44
  • \$\begingroup\$ They seem to line up, and in the socket there's screws in place but when I remove them, nothing comes off so I don't think they hold anything together. The cord's screws are too short to reach the receptacle so if I can figure out the thread sizes, indeed, a little bit of extending should do it. But these connectors feel very robust and tight, and because the cord comes out of the plug in a 90° angle rather than straight, it would be very difficult indeed to make it come off accidentally. Even pulling the cord doesn't move the plug at all, you have to pull directly from the plug to detach. \$\endgroup\$
    – user158589
    Apr 27, 2018 at 14:13
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They are retention clips to ensure the connector doesn't get yanked out or fall out. If you look at the other header you will see a slot where the clip will fit.

This kind of thing is common in older connectors (though the side screws are more common) that didn't have a internal spring providing the interference fit.

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    \$\begingroup\$ My socket and cord are of a different maker, and while the socket has those loops, there's nothing on the cord for them to interact with. This is why I couldn't see their point. So since they've got nothing to do with panel mounting, I think I can just remove the loops as they serve no purpose in my setup. \$\endgroup\$
    – user158589
    Apr 27, 2018 at 13:40
  • \$\begingroup\$ Those 'loops' are not the IEEE-488 latch standard, which is a kind of retention screw with a threaded head for stacking. \$\endgroup\$
    – Whit3rd
    Apr 27, 2018 at 23:22
  • \$\begingroup\$ @Whit3rd Oh I see. Well these terms are confusing as it can be hard to know what aspect of the product each term refers to, especially when you don't work in the field in any way... I guess my cord is IEEE-488 then because it has stacking screws and that plug that has both male and female connectors, for stacking. Since you can plug that cord into the socket that has those retention clips and it's not IEEE-488, what is it then? Does IEEE-488 refer to the stack aspect instead of the mating parts? \$\endgroup\$
    – user158589
    Apr 28, 2018 at 9:02
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    \$\begingroup\$ @user158589 IEEE-488 and HP-IB call for a kind of connector wired to specification. All the latch parts are accessories to that connector (Amphenol micro-blue-ribbon 24 position), and the wire-type is just one kind of accessory available for non-488 connector applications. \$\endgroup\$
    – Whit3rd
    Apr 28, 2018 at 17:53

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