Unable to connect to CTouch

I currently can't program my touch screen from either my desktop or notebook PC.
(Note, my older notebook worked with ctouch but I've sold it).

Desktop PC.
I have two serial cables running to my desktop PC, one from minder and one from ctouch. Minder works fine, but I cannot connect to my ctouch screen ('Could not connect to ctouch unit'). I'm using the same serial port and cable that I use for minder so it's not the cable. The faq talks about serial ports with low voltages, would this explain the problem even though minder is fine?
The PC is only 12 months old and running XP. It has an expensive motherboard with serial ports on it.

NoteBook.
My new notebook has no serial port. I bought a USB-serial adaptor which works fine, but again cant talk to ctouch. I believe there is one recommended adaptor to use, and I've been looking but it's not in the FAQ. What's the make?

I would rather just get my desktop working than buy another damn USB adaptor, so maybe I should try installing a PCI serial adaptor card?


And I have to say I was very disappointed when I rang tech support. The person I spoke with was short with me from the outset and bordering on rude. His only deduction was that it was my PC (even though the serial ports work with everything else I use, including minder) and I had to try a different PC. Not very helpfull as I am not going to throw away a fairly new $4000 PC.

I would really appreciate it if someone gave me a more detailed explanation of why it is my PC, and why the voltage levels affect comms (I assume it's to do with the length of the serial cable). Don't be afraid to get too technical. Then maybe I can come up with my own ideas about getting my desktop PC to work, although any suggestion would be appreaciated.

I have also tried to program it via the Minder connection to cbus, and although I can connect and reset the touchscreen, I still get an error when trying to download (I think the text was the same).

Many Thanks,
Brad.

 

You say you have TWO serial cables, then you say you are using the SAME cable. Which is it ? Do you mean that when you do use the same serial port and cable as you do for Minder, then it still doesn't work ?

This could be the cause of the problem. C-Touch uses the voltage on the RS232 handshaking lines to power the COM port. If this is low, then the serial comms may not work.

See http://www.clipsal.com/cis/lit_installtraining_connectors.php3

You could give that a try. They are quite cheap these days.

There are lots of problems with getting high performance from serial ports on PCs. Many of these are related to the ports being not quite compatible with the RS232 standard. If you run at low data rates, you have no problems, but when you run at high data rates, these incompatibilities start to become an issue.

Have you also tried adjusting your serial buffers (as described in the FAQ) ?

 

The two serial cables run from each of Minder & C-Touch to seperate RJ45 ports in my study. I then use one serial cable to patch my COM port between the two RJ45 ports.

I have tried adjusting the FIFO's on the UART, and I've tried each of the available COM ports.

Out of interest, what baud rate does CTouch use?

I'll try either the PCI serial or the Dontronics USB adaptor and let you know how I go.

Thanks for you help.
Brad.

 

How long is the cable from your PC to the CTouch totalling all cables together?

 

So you actually have two separate cables to Minder and C-Touch. It is quite possible that the fault lies in the cable between your C-Touch and the RJ-45 connector (wallplate ?).

If the cable is more than around 5 metres long, this may also cause problems.

38,400 baud

I am concerned that this may be a waste of time. The most likely cause of the problem is the cable to your C-Touch.

I would suggest connecting the C-Touch to your computer via a normal (short) cable and verify that the C-Touch and your PC will communicate. If they do communicate properly, then the problem lies with your cable. If they don't then the problem lies elsewhere.

 

The cable from CTouch to the wall plate is probably around 20 meters, maybe up to 25 meters. The patch cable from the wallplate to the COM port is about a meter.

Remember though that I was always able to program it from the same location as my desktop using the notebook that I sold.

I've ordered the Dontronics USB adaptor. We'll see how that goes.

Brad.

 

This sounds like the aforementioned voltage problem, which would be exacerbated by voltage drop over a long serial cable. Your old notebook probably had higher RS232 voltage, so was unaffected by the distance.

 

With lengths like that you really should be using line extenders to boost the RS232 comms. For the sped that CTouch communicates at that it too long to guarentee reliability in comms.

 

20 meters is getting close to the limit for RS232 at 38,400 baud.

The real question here is not "why doesn't it work", but "how on earth did it work before ?"

 

COM Port

Stab in the dark, have you enabled it in the PC BIOS?

This is simple, but easily over-looked?

 

We have experienced problems as you describe, but found that the problem with the connection, lay in the set up of the communication port. I cant remember exactly how we rectified the problem.

Our old laptop which we had used to connect and program several touch screens, developed a cmos fault, when we sorted this fault out we found it would connect to c-bus but not to c-touch. We even connected direct into the screen,(not using our 12m remote RJ45 cable) still would not connect. After general swapping and selecting ports we finally got it to work. have you checked Options Tab , program options, connections. try altering the ports, i am sure that is how we rectified our problem.

I bought a new laptop P4 2 gig, by mistake I forgot to check for a serial port, so i bought a usb port replicator, that didnt work so i bought another, both would sort of work but missread the data and rubbish letters and numbers would be put into the address etc. so I bought another laptop this time with a serial port. I havnt used it yet, because I like to use the old laptop, nice feel to it.

 

Oh well, as you would expect the dontronics USB adaptor made no difference.

I've broken the ctouch programming cable into my pantry (right behind it) and naturally it works - so that'll do me!

As a wise man has said - its probably more a question of how did it possibly work before.

Thanks for everyones responses.

Brad.