I need to connect a flow meter to a desktop which sits about 75 feet away. On the meter side, a round jack plugs in to the side. The opposing end is DP9. This cable is only about 2 feet long. I came across these RJ45 to DP9 adapters at ACK. I figured running CAT5 would be better than trying to find 75 feet of serial cable. I've googled the pinout for the adapter, but find about a dozen ways that say they are the "normal way." Figured I run it like this:

Flow Meter(Round Jack)===>Male RJ45 adapter===>Female RJ45 adapter===>Desktop

I was hoping to find someone that might have a little bit of knowledge about these adapter. Any help would be greatly appreciated.

Thanks for your help!
Stevens
:toast:

I wish I could answer easily, maybe someone else can. If you don't get anything helpful soon you might post this question in cabling section.

Get a breakout box at a good electronic store.
Mike Sandman has a automatic serial cable
mikesandman.com

Check here https://www.arcelect.com/rs232.htm

It gives you all the info you need to get things up and running.

EIA-561 is what you are looking for.

We build RJ45 to DB9 adapters every day. Are you just trying to extend your meter's cable that has the DB9 on one end? How many pins on the round connector? You need to make sure that the cable doesn't use more than 8 leads or CAT cable won't work. I think your best bet would be a DB9F to DB9M extension cable. If you can't find one, let me know. We can build you one.

The connector has 6 pin. Already thought that one out . And yes, I'm trying to extend the cable without purchasing a 75 foot serial cable. I have boxes and boxes of CAT5. Plus this cable is going in a brewhouse and there is a good chance someone will cut/break/burn it at some point and replaceing CAT5 will be quick once I figure this pinout... hopefully.
The flow meter is a Teledyne ISCO 4230.
The cable end that attaches to the meter is 6 pin M/S (don't know what M/S is, just reading from manual)
Cable labed "ISCO 602544044 INTERROGATOR CABLE 9 PIN/PC REV K GI 2506"

Well it sounds like all you need to do is make a straight through LAN cable and get two DB9 to RJ45F adapters. As long as the adapters on each end are the same and cover all 6 pins on your meter, you're good to go.

You could also go to Radio Shack and buy DB9 connectors and simply pin them out yourself using CAT5. They have DB9 crimp connectors for about $2 each. If you can crimp, go for it.

So, if I just make the adapters match cable pinouts from the rj45 to db9 and the db9 to rj45, and put a striaght thru cat5 cable, I should be good to go.?
Why do I try and make everything so difficult???

From my edit above:

You could also go to Radio Shack and buy DB9 connectors and simply pin them out yourself using CAT5. They have DB9 crimp connectors for about $2 each. If you can crimp, go for it.

Radio Shack

I don't know if this is an RS232 serial interface, I suspect that it is. If so there would be transmit and receive pairs and they may be shielded in the factory cable. You could try your CAT5 if you want but don't be surprised if it doesn't work.

-Hal

RS232 is all about speed at a distance, I believe the spec length is 25' for full speed. If it is running at lower speeds then the distance is ok, most monitoring equipment runs at 9600 baud, which MAY be ok for 75', it is pushing it. I too would suggest the DB9's on either end, less parts means less to go wrong.

Actually theres a little more to it than just speed. I deal with a lot of rs232 connections to termservers and concentrator hubs, mostly i buy from digi.com. Anyhow here is link with a brief breakdown in regards to cable specs. You may also find the right pin-out for your db9-rj45 connection on that site also, i only do db25-rj45

~r


https://ftp1.digi.com/support/termi...60int/cabling/cabling_specifications.pdf

All db9 to 8 pin modular are not alike.
Besides the male/female issues you have to look at the internal wiring, WECO or USOC.
I would make a db9F to db9M straight through if you want to avoid problems. Specs are 50 foot max but 75 feet should work if you are not at 19200.

Alright, I wired the adapters matching pin to pin, put an over-the-counter 4 foot cat5 patch cable between them, and connected this frankenstien cable to my laptop with the FlowLink software installed. It worked. Connected and retrieved the data quickly. I am running the full size cable to the workstation from the flowmeter today. With any luck, it to will work an I'll post a follow up.
Thanks,
Stevens

Specs are 50 foot max...

This is a common misnomer that does not take into account new cable technologies (i.e. cat5). We have plenty of terminals between 200-300'/9600 that run fine.

It's not a misnomer it's a spec.
Yes it will work beyond 50 ft.
If you look at old Comdial documentation they support 500 feet on a serial cable.