Topic: Plug (or socket) for Campbell Scientific SR50a

[DaleReid]

I have purchased a used Campbell Scientific SR50A ultrasonic ranger and with a replacement transducer, have it functioning.  Nice little unit.

When I got it off eBay, there was no plug to screw into the socket on the device (or socket, since the device has pins that go into the cable end).

I have been testing it with the datalogger/terminal emulator wired to a connection block on the circuit board.

I went to Campbell's site and they want nearly $150 for a cable 10' long.  That's three times what I paid for the device!

Does anyone know what kind of connection system they use and maybe I can find a plug for less and wire it myself? 

Does anyone HAVE some otherwise not useful to them short cable and plug to attach to such devices (I don't know if these are unique to the SR50a or might fit other Campbell stuff), and would be willing to sell to another hobbyist for less than a car payment?

Any leads or help would be appreciated.   Dale

[EA1EF]

not have here any detailed photo but the connector must be a standar connector such C016 or similar used in RS-485 industrial lines

The original ones are inox and weatherproof excellent quality. Cable probably too.

may be use a plastic one with extra vulcan tape and study carefully the wiring diagrams because i see only info about colors and none about pins connector

[G.Brown]

it ...
https://s.campbellsci.com/documents/us/miscellaneous/old-manuals/SR50A%20Distance%20Sensor.pdf

looks like some sort of latching connection - havent seen one before.
perhaps an 5 pin aviation socket could be made to fit and sealed with self emalgy

[EA1EF]

On pdf manual cant see connector photo. I search a photo taken days ago it seems like

threaded connector RS M18 10pin (compare google photos)

Not sure if its 18 mm or 1 1/8

Its rare to find to buy in aerial and weatherproof versión but not impossible

https://www.sensata.com/products/position-sensors-encoders/connectorscable-assemblies-m18-10-pin-connector-31186-1810

https://es.rs-online.com/web/p/conectores-circulares-con-especificaciones-militares/0475864?cm_mmc=ES-PLA-DS3A-_-google-_-CSS_ES_ES_Conectores_Whoop-_-(ES:Whoop!)+Conectores+Circulares+con+Especificaciones+Militares-_-475864&matchtype=&pla-306962928953&gclid=Cj0KCQiAxc6PBhCEARIsAH8Hff006g1taxPe72T6H_XRh94LBCe64WbpN8IW3hDF86JA3Xg_-TfMzOMaAtHYEALw_wcB&gclsrc=aw.ds

etc etc

risky buy on aliexpress such here

https://es.aliexpress.com/item/32620267150.html

18-1s -  male insertion - straigt plug

needed wiring diagram with colors and dimmension of the connector

[G.Brown]

..the photo is right at the bottom of the page/manual

it would appear to latch rather than screw together...

[DaleReid]

I am not a great photographer, but I have taken pictures of both the plug to interface with the outside world, and the internal terminal strip on the SR50a circuit board.  Whether or not the colors of the internal wires match to the colors in the external cable or not, I cannot be sure, but looking at the suggested wiring diagram that is generated by the ShortCut program to hook up to the Campbell Data loggers, I would guess they would.

This terminal strip shows two connections which have no wires, and are Temp + and Temp -, which I assume is for the version which has built in temperature correction, hooked up via an external thermocouple, a 107 or 109 I think.  I assume that they would not put the components and firmware on the standard SR50a to make it work if you just hooked up a probe to those terminals.  And there were no wires running back from the plug to attach to them.  Getting to the base of the plug to attach wires would approach being impossible.  When I took the plug off a unit, the potting rubber was so incredibly difficult to remove it basically destroyed the plug, taking a half hour with diagonal cutters, razor blade knife, and heavy duty needle nose pliers.  Exceptionally difficult.  And to reassure those interested, I did NOT ruin a good unit be doing so, this top was corroded from exposure and would not have been functional no matter what.

Here is the terminal strip, just as Campbell Scientific shipped it, with their wiring as done during manufacture.  (another posting will have the plug and pin connection).
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[DaleReid]

Here is a picture, or attempt at least, to show the 10 pin plug.  The socket is secured by a screw thread, not a simple quarter turn and lock on the socket.

I looked at the links from EA1EF, and could not find a manufacturer's data sheet showing the correct pin identification or numbering.  The way I numbered them is explained below and is almost certainly NOT the official pin number.  I don't know if my antivirus software blocked a couple of .pdf downloads or why I couldn't find the official pin designations.

The picture shows the plug as seen if the top of the SR50a is at the top of the picture, and the little index is at the top, too.  There is another index at the right side, about the 5 o'clock position.

The top two pins are numbered in my scheme, as 1 to the left and 2 to the right.  I then dropped down to the next row, with three pins, and again starting at the left assigned 3,4,5.

The next row of three pins is 6,7,8

Finally the last row of two pins is 9, 10.

While there may have been some other molded in markings that I just couldn't illuminate to take a picture, there is one pin, number 7 in my scheme, with a "10" being shown, so I'm pretty sure the official pin numbering is far different, but for my purposes I am telling you what is connected to the pins

IN MY SCHEME:
Pin 1, Black wire, Ground on the terminal strip
Pin 2 Green Wire, SDI-12/RS232 Tx wire on the terminal strip
Pin 3, Red wire, +12v on the terminal strip
Pin 5, White wire, RS232 Rx on the terminal strip
Pin 8, Clear wire/shield,  Shield on the terminal strip.


Here is my attempt at labelling the pins as I assigned numbers

            1     2
       3       4      5
       6       7       8
            9     10

Note in the picture there appears to be '10' molded into the plastic at the base of the pin, so I am hoping someone can find a professional drawing with the real pin designations on them.

Also, I found a cable assembly as pointed out in the previous links on this subject, but the socket and a cable premade costs about $170, which is too rich for my blood and is about three times what I spend for the SR50a.

Digikey has what looks like to be the right socket to wire up, but I cannot get the pictures to download, and that socket is about $20.


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