Com problem with V124 (AREV Specific)
At 06 DEC 2001 05:35:44PM Tom Ayers wrote:
I have been using a communication routine that uses v124 to read a barcode reader since 1992 without problem. It has always been very reliable. The old system was a 486 running DOS 6.22.
We upgraded the stockroom to a "new" computer. It is running Win98 on a PII 400Mhz. Now it will randomly drop characters, typically 0 (ascii 48). I searched through old messages here, and it appears that this has been discussed before, just not resolved. Here is the link to the old messages: http://www.revelation.com/WEBSITE/DISCUSS.NSF/7a591c01171830eb8525652b0083c06b/8b10d3dfdebc42e5852565f0001e2924?OpenDocument
Is there a solution to this, or a good workaround? Going back to dos is not a good option for us here (stockroom needs windoze stuff for other things). I need this back up and running as soon as possible!
We are running Arev 2.03 on Novell 3.12 with NLM 1.5
Thanks,
Tom Ayers
At 06 DEC 2001 06:00PM Bill Titus wrote:
I'm not a serial port user, but I like searchin' for stuff. This looks interesting.
http://barcodestore.com/software/commdrv/
Bill
At 06 DEC 2001 09:44PM Tom Ayers wrote:
Thank you, but I would like to just (quick) fix the v124 problem. This is an existing program from nine years ago with v124 calls all over it.
If I can't get v124 to work, I will probably need to buy something like this. I would prefer to avoid the rewrite.
Thanks,
Tom Ayers
At 07 DEC 2001 08:57AM Don Miller - C3 Inc. wrote:
The problem isn't in AREV. The problem is the way that windows multitasks programs. It doesn't care about v124 and what it's doing. From the outset, many time-critical programs running in DOS boxes have had to be completely re-written (and even then, many do not work satisfactorily). I doubt that RTI would make such an effort in this case, especially given the problematic outcome for the results.
Don
At 07 DEC 2001 10:42AM Warren wrote:
Sounds like a job for Steve Smith or the Mighty McNerthy…
At 07 DEC 2001 12:15PM Don Miller - C3 Inc. wrote:
I don't think even they can completely solve it. Multi-tasking is handled differently in various flavors of Windoze and I'm not sure that it is possible to alter that. It is possible to have multiple time-critical processes running in various windows or in the background desktop. V124 sometimes has problems if 100mb ethernet is running, god forbit high speed TCP/IP.
Don
At 07 DEC 2001 02:57PM Warren wrote:
Updating V124 to use the UART 16550 spec might help considerably. Back in Win3.1 days replacing MSFTs stock comm drivers with third party drivers that used the 16550 spec alleviated most modem and serial printer problems.
At 11 DEC 2001 10:58AM Dean Todd, Computer Resource Team - Orlando wrote:
How about using a barcode reader that doesn?t use a serial port?
Symbol Technologies and others offer readers that attach between the keyboard and the computer, using a device called a ?wedge,? ? no drivers or software required and it works in DOS, Windoze, Linux, whatever.
The reader doesn?t care about the OS because the wedge contains the on-board smarts to convert barcode data into keystrokes.
At 11 DEC 2001 08:04PM Tom Ayers wrote:
I came up with a messy but workable solution:
After some testing, I found that V124 was dropping ascii zero (48) every time. Every other character was fine (I didn't test all 255, just the letters, numbers and control characters). My barcode reader has an option to substitute one character for another, so I subbed in ascii 127 for 48. On the Arev side, I just swap them back. Works every time under win95 and 98 now.
Now for the questions:
Why just the zero character? If this is a timing or multitasking issue as discussed, wouldn't it be a random selection of characters dropped? Upon questioning the stockroom, they told me it hasn't worked in a very long time, even though they were running pure dos 6.22 (no windows at all). I just found out about it now, as we upgraded their computer. I revived the stockroom's old system for testing. It is a P100 with 8mb ram, dos 6.22, accessing our Netware 3.12 server with vlm and odi drivers, the nlm tsr and Arev 2.03. It failed in exactly the same manner (dropping zeroes).
The only change that I know of between 1992 (when the barcode reader worked flawlessly), and this system is the addition of the NLM.
Could this be a NLM issue?
Tom Ayers
At 11 DEC 2001 09:31PM Warren wrote:
Can you install a local copy of ARev on a Win9x PC and run it without the NLM and TSR. And create a test program (in ARev) to use the barcode reader?
How about if you bypass ARev all together and try the reader in say a test program that came with the reader. Maybe it's a problem with the reader or the 'wedge' program that the reader uses and not V124 at all.