MSComm and a Scanner
in [Visual Studio]
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From: Dave on 1 Dec 2006 22:39 Currently I use the MSComm control to read a Symbol (HotShot) scanner and everything works fine. The only issue is that MSComm only reads the scanner 3-4 minutes after scanning. I figured it's an internal timer thing and due to the fact that the operator only needed to use the scanner every half hour or so, this has never been a problem. Now, however, we are expanding the use of the scanner to other operations and the 3-4 minute delay will be a problem. Mainly because we are going to have the scanning process power up a machine and they won't want to wait the 3-4 minutes for MSComm to read the scan. This is a Vb 6.0, Win2000 environment. Could anyone advise me how to either change the MSComm time cycle or let me know of another control that offers more flexibility. There are no properties which look like they control the cycle time of the MSComm, am I wrong on that? Thanks for any insight. Dave
From: Jim Mack on 1 Dec 2006 23:12 Dave wrote: > Currently I use the MSComm control to read a Symbol (HotShot) scanner > and everything works fine. The only issue is that MSComm only reads > the scanner 3-4 minutes after scanning. I figured it's an internal > timer thing and due to the fact that the operator only needed to use > the scanner every half hour or so, this has never been a problem. > Now, however, we are expanding the use of the scanner to other > operations and the 3-4 minute delay will be a problem. Mainly because > we are going to have the scanning process power up a machine and they > won't want to wait the 3-4 minutes for MSComm to read the scan. > This is a Vb 6.0, Win2000 environment. > Could anyone advise me how to either change the MSComm time cycle or > let me know of another control that offers more flexibility. > There are no properties which look like they control the cycle time of > the MSComm, am I wrong on that? Cycle time? You're going to have to show some code or at least describe the program logic. 'Cycle time' is not a property of serial comms in general or the MSComm control in particular. Do you have a timer in play with a period of 3-4 minutes? -- Jim Mack MicroDexterity Inc www.microdexterity.com
From: Dave on 2 Dec 2006 01:04 Jim Mack wrote: .. > > Do you have a timer in play with a period of 3-4 minutes? Jim, Thank you for your prompt reply. There is no timer control in play. I can post code but I do not believe this is a code issue. I simply have a textbox on a form that dispalys the scanned string. If I go out into the shop (where the scanning is done), and scan the data string, I will walk back into my office and it will take that long (3-4 minutes, I haven't timed it precisely as it's not been a problem ubtil now) for the scanned string to show up in the textbox. i.e.....MSComm sends out a signal to the com port every 3-4 miinutes for a read. I simply need to shorten that inerval to seconds instead of minutes. Thanks, Dave
From: Jim Mack on 2 Dec 2006 01:25 Dave wrote: > Jim Mack wrote: > . >> >> Do you have a timer in play with a period of 3-4 minutes? > > Jim, > Thank you for your prompt reply. > There is no timer control in play. > I can post code but I do not believe this is a code issue. I simply > have a textbox on a form that dispalys the scanned string. If I go > out into the shop (where the scanning is done), and scan the data > string, I will walk back into my office and it will take that long > (3-4 minutes, I haven't timed it precisely as it's not been a problem > ubtil now) for the scanned string to show up in the textbox. > i.e.....MSComm sends out a signal to the com port every 3-4 miinutes > for a read. But that's not how MSComm works. Something else is going on here -- either the scanner itself is set to produce an output at intervals, or there is program logic (or a timer) that causes that delay. MSComm by itself will never send anything out to a scanner or any other device. Your program code does that, and that's where you have to look. -- Jim
From: J French on 2 Dec 2006 03:12
On Sat, 2 Dec 2006 01:25:48 -0500, "Jim Mack" <jmack(a)mdxi.nospam.com> wrote: <snip> >> i.e.....MSComm sends out a signal to the com port every 3-4 miinutes >> for a read.=20 > >But that's not how MSComm works. Something else is going on here -- = >either the scanner itself is set to produce an output at intervals, or = >there is program logic (or a timer) that causes that delay. MSComm by = >itself will never send anything out to a scanner or any other device. = >Your program code does that, and that's where you have to look. Maybe the RS232 is really running through a network and there is some sort of buffered timeout on the send side. I've seen similar stuff with printers taking an age to start. |