Hi,
I’m trying to test my SSC-32 using the Lynx SSC-32 Terminal freeware that is available for download, and I can’t get my computer to communicate with/recognize the SSC-32.
I’ve read pretty much all of the posts on this forum and I’ve tried everything suggested, which leads me to believe that I have a garbage USB-serial cable. I’ve tried two different cables (although both were cheap ones) to no avail. Could anyone give me advice on specific USB-serial cables that have worked? Thanks…
Gotta start somewhere… Does the green LED light up?
We recommend using name brand cables. Belkin, Baffo, I/O gear, etc. Are you using a laptop? Have you used the cable successfully before?
This is really the best solution ever… No kidding!
lynxmotion.com/images/html/build126.htm
Yup, the green LED lights up, and I’ve verified 5V DC across the regulator. I just can’t get the green LED to go off when I send strings in the test terminal, and it can’t find the SSC-32 card when I hit the “Reg.” button. I’ll have a look for one of those cables.
I haven’t used the cable successfully before, but the grad student working on the project before me (who never answers my emails) had success with it on a different PC (I’m also on a PC).
Re: Serial port card - That’d probably be a last resort; I’m already kind of over budget on my MSc. Thanks again for the help…
If the light is not ever changing from solid on then it is unlikely you are ever getting anything to the SSC-32. This isn’t the “classic” latency issue most people experience with USB-to-serial translators. It is more likely a configuration error such as wrong comport selected or wrong baud rate, or jumpers on the SSC-32 not configured for RS-232 communications.
Do you know how to make a loop-back connection at the DB-9 of the USB-to-serial translator and verify serial data is getting out and back properly?
Ah, now we know it’s been used, not part of a new kit. Another thing to look at is the jumpers by the DB9 connector. There should be two of them installed and they should all be vertical when you can read SSC-32 on the board.
I’ve messed around with the configurations and made sure that I had the right com port selected, the right baud rate, etc… I’ve done so by making sure that the Device Manager settings on my PC sync up with the ones in the Lynx SSC-32 Terminal. Does that make sense?
All of the jumpers are as they should be according to the manual as well, i.e. I made sure that everything’s good for 115.2k baud rate and DB-9 jumpers are in the right place for PC use.
No, I’m not sure what you mean here (sorry, I’m kind of new to all this). How would I go about doing this? Thanks again…
Yup, everything looks ok in that respect, thanks again for the reply…
A loopback simply connects the TXD pin of the serial port to the RXD pin so that anything typed out is looped-back in. It is a way to establish serial data is both getting to the TXD connector pin and back in from the RXD pin at the same time.
On a DB-9Male pin 2 is RXD and pin 3 is TXD. So connect those two and use a program like hyperterminal to verify what you type is repeated back. Actually usually you test it without the connection to make sure local echo is turned off (a terminal setting that types locally what it sends out the port), then make the connection and verify the loop-back works.
Note: It’s important that you have any sort of flow control set to off or none since there is no flow control being used.
So if the loopback works then you know you have the com port assigned to the USB adapter correctly identified and the troubleshooting moves back more towards other settings and maybe hardware.
You may want to go to Radio Shack and get a female DB9 connector like below and solder test wires on the commonly used pins (tx, rx, and ground) for testing. In lynxterm, be sure to check the comport being used in the dropdown to see if it is the usb adapter. I have two usb adapters attached to my laptop, and the internal modem is also in the list (usb adapters are usually com5 and higher). Lynxterm will probably set the comport to the baude rate selected in it and not use the device manager default. I bought several of the below usb to serial adapters last week when on sale for $2.99, and they seem to work ok with the ssc-32 (the tx is 0v-5v instead of ±12v) for simple I/O.
hey zoom whos driver are those using?
Not much info: driver by WCH, shown as USB-SERIAL, copyright 2001-2007.
I tried the loopback test in Hyperterminal and got it to work, and just for kicks I figured I’d try loopback tests in NI’s Measurement and Automation Explorer and also in Labview. Worked fine in Labview, but crashed M & AE every time I tried to access the device. Not super important right now, but might be a problem somewhere down the road…
I think this means I’m more or less back to square one, or at least to the “other settings and maybe hardware” part of the troubleshooting. Any more ideas? Thanks again for the help…
At this point you need to try the loopback test with LynxTerm, then connect the SSC-32 to see if you can get the green LED to go out, and then blink when you type. Try typing VER then hit enter. The SSC-32 should report back the firmware version number.
Ok, I did the loopback test on LynxTerm with the USB-serial cable only, and I had (what I think is) some success. When I type “ver” as a test either “ver” or “vveerr” comes up in the command window, depending on whether I have local character echoing turned on or off. If I move the right-side slider bar around, the new positions are displayed in the command window, which I’m assuming is a good thing.
Then I hooked up the SSC-32, and as before, green LED comes on but I can’t get it to go out or blink. Typing “ver” doesn’t return the firmware version number, either. What’s worse is that when I disconnect the SSC-32 and retry the loopback tests with just the USB-serial adapter, nothing works (on Hypeterminal, Labview, LynxTerm, etc.) - I have to turn off everything and reboot to get the USB-serial loopback tests to work again.
ok remember with all of this testing you are doing you may have left programs open when you have tried other programs. This is not a good idea because most programs that use the serial port, open it at startup, and will not let any other application have control of the serial port until it’s closed. The VVEERR is a very good thing with Lynxterm. Has the DB9 connector been stressed? I have seen where some connections were broken on the DB9 connector if it’s pulled up from the board.
Yup, I’ve been really careful with closing/disconnecting other programs before doing loopback tests with any others; the problem only seems to arise when I connect the SSC-32 card and try to use it.
The DB-9 connector hasn’t been stressed unless it happened during shipping. I just looked, and it seems fine. I’m using a brand new SSC-32 that I got a few days ago to replace one that I thought I’d fried. Turns out the other one probably wasn’t fried, as they both seem to have the exact same problems when I try to use them. Thanks again for the help…
Holy cow, I think it’s working, and it was the easiest thing in the world. All I had to do was connect and power up the logic and servo power on the SSC-32 before I turned on my computer, and then turn on my data aquisition system AFTER the computer was turned on. I’m happy now, but any idea on why the order mattered so much? Thanks very much to everybody for the helpful comments…
Not sure. We don’t have any order requirements for power up. It must be something specific to your set up.
What is the manufacturer and model of USB-to-serial adapter you are using?
It is more than a bit odd that you had to shut down and restart your system to restore functionality to the USB-to-serial adapter when at most you should have needed to unplug it from the PC, wait a few seconds until you heard the PC acknowledge that it had been unplugged, and then plug it back in.
If you got it to work for you that’s great… I would like to suggest you try using it from an externally powered USB hub. If there is something about the adapter, maybe it was damaged from the previous user, that allows it to draw more power than it is supposed to it could be in turn damaging the USB root hub in your PC. That, or really seriously crappy drivers are about the only ideas I have on how a USB device could require you to actually cycle the power to your PC to restore its operation.
I noticed late night that when my laptop went went into power saving mode, one of the two usb serial adapters was not recognized when the laptop came out of power saving mode. See the same thing from time to time with my usb wifi adapter.
