Errors on COM link to Win 7 PC

[g0hdb]

Hello all, I hope someone can help...

I've recently started to use my AIM-4170C in conjunction with a PC running 32-bit Win 7 Professional; I'm currently using the latest v9.10B software for the AIM. I'm using an FTDI-based USB-to-serial adaptor with the latest FTDI driver (2.12.0.0 of Aug 2014), with the virtual port set to COM6 and the port latency timer set to 1msec.

When I do a calibration run or a scan, an error message often appears, in red, in the top LH-corner of the screen; the message is:

"No data from I/O port 6
numchar=71 numpts=16"

Also, occasionally I see a '### Data error ###' message.

Previously I used the AIM with a WinXP PC with a Prolific-based adaptor and the v8.65A s/ware and I don't recall ever seeing any error messages relating to the COM port.

Fortunately the error on the Win 7 PC seems to be non-fatal and the serial comms link between the PC and the AIM seems to keep working despite the error message appearing, although sometimes a scan will terminate early for some unknown reason. Even if the COM port error message appears during a calibration run, the 'Checking cal data' function seems to run successfully so presumably the data generated by the cal run is OK.

I've tried using the v8.65A software on the Win 7 PC and I get the same error messages so the problem seems to be related to Win 7 and/or the FTDI adaptor and driver rather than the AIM s/ware. I've also tried the AIM, with the FTDI adaptor, in conjunction with a laptop that's still running WinXP and the errors don't seem to occur with either v8.65A or v9.10B. I've also tried increasing the COM port's latency timer to 10 or 20msecs, to no avail - the error message still sometimes appears.

Although I can live with the occasional error messages because the problem seems to be non-fatal as far as the s/ware is concerned, it's mildly disconcerting and it's also inconvenient to have cal runs and scans terminated early.

Has anyone else experienced similar problems when using an FTDI-based adaptor in conjunction with Win 7? If so, has a remedy been identified??!!

73 and thanks in advance,
--
Martin G0HDB

[smokchsr]

I'm still on XP with a real RS232 port, so I haven't seen what you describe, but what I have seen is that there is any delay in receiving the data from the serial port you will get an error. In my case it took a while but I finally isolated it to WiFi adapter. What appears to have been happening is if I left the WiFi adapter enabled, when I'd take the laptop in the field to test, apparently it was doing an (or excessive) interrupt on the com line, as it was trying to trying to find a signal. Note Wifi enabled and connected didn't cause any problems, only when it was searching would the AIM error out.

So long story short, I'm guessing that for some reason on that PC you are getting some sort of delay on the comm bus. Now determining if it's win7 or something else in that PC could be challenging. If it has on board WiFi, you might try disabling that and see what happens.

[n8aum]

My 4170D always goes out to lunch with "no data" from com when I try to do a high res cal and increase the resolution to something higher than the defaults.
Running Winblows 7 ultimate 64 bit.

Vidas