Navision/MsComm32 Integration

JackEoh

I need help communicating with a serial device using MsComm32.ocx

MsCom.InBufferSize := 1024;
MsCom.OutBufferSize := 512;
MsCom.Settings('9600,n,8,1');
MsCom.CommPort:=8;
MsCom.PortOpen(TRUE);

MsCom.RThreshold := 1;  
TimeOutCount := 100;
REPEAT 
SLEEP (1000);
TimeOutCount -= 1;
UNTIL (MsCom.InBufferCount >= 1) OR (TimeOutCount <= 0);

That is what I currently have to trigger the rest of the code. However, it does not seem to register the input at the moment.

The device in question is a PSC handheld Scanner. The scanner functionality sends a string through the serial port, and awaits a response (another string) then passes yet another string back containing the data.
Any help/tips/advice at all would be greatly appreciated!

Edit: The problem was with the setup of the comport. Because the device was using an RS232 port, a COM port could not just be opened. As we have created a solution through VB, I don't know the specifics, but there are a series of settings that use GUID's to set the COM port before it can be interfaced. This, apparently, would be possible in NAV.

kine

For me it is easier to create own application in Visual Studio using the standard Serial port component. You can create small application which will change your scanner into "Keyboard" scanner. It means it just read the data from scanner and using SendKeys function will send them into active application. For this base functionality you need just few lines of code...

Revolution1210

As we can't use an event driven method using the mscomm32 directly, the next best thing is to use the Navision Timer automation controller (with events) and poll the InBufferCount

In terms of initializing the mscomm32 control, you should be ok to leave most properties at their default values.

However, you may find you need to play about with the following in order to get it working with your particular device/scenario:

.InBufferSize
.OutBufferSize
.Settings

I found the following settings worked in my particular case:

CommCtrl.InBufferSize := 1024;
CommCtrl.OutBufferSize := 512;
CommCtrl.Settings = '9600,n,8,1';

Open the COM port to communication:

CommCtrl.CommPort := 1;
CommCtrl.RThreshold := 1;
CommCtrl.InputLen := 1;
CommCtrl.PortOpen := TRUE;

The code within the Timer event may look something like this

IF CommCtrl.InBufferCount > 0 THEN BEGIN

  CommCtrl.RThreshold := 0; // Switch off receive event

  Buffer := CommCtrl.Input; 

END;

CommCtrl.RThreshold := 1;  // Switch on receive event

JackEoh

Revolution1210 wrote:

As we can't use an event driven method using the mscomm32 directly, the next best thing is to use the Navision Timer automation controller (with events) and poll the InBufferCount

In terms of initializing the mscomm32 control, you should be ok to leave most properties at their default values.

However, you may find you need to play about with the following in order to get it working with your particular device/scenario:

.InBufferSize
.OutBufferSize
.Settings

I found the following settings worked in my particular case:

CommCtrl.InBufferSize := 1024;
CommCtrl.OutBufferSize := 512;
CommCtrl.Settings = '9600,n,8,1';

Open the COM port to communication:

CommCtrl.CommPort := 1;
CommCtrl.RThreshold := 1;
CommCtrl.InputLen := 1;
CommCtrl.PortOpen := TRUE;

The code within the Timer event may look something like this

IF CommCtrl.InBufferCount > 0 THEN BEGIN

  CommCtrl.RThreshold := 0; // Switch off receive event

  Buffer := CommCtrl.Input; 

END;

CommCtrl.RThreshold := 1;  // Switch on receive event

Thank you very much for the response
However, I had already searched the forums and read that response, it's the InBufferCount I'm having issues with. It doesn't seem to be triggered when the handheld sends an output

kine

Try to configure the scanner to send Enter character after the barcode. You can configure the scanner through special barcodes from the manual.

JackEoh

kine wrote:

Try to configure the scanner to send Enter character after the barcode. You can configure the scanner through special barcodes from the manual.

The scanner is using a different companys software, which we can't get access too. Therefore it cannot be modified. However, NAV doesn't seem to pick up any data from it at all. I do currently have a colleague writing an interface for it in VB, but it would be nice if I knew where I was going wrong really!

ta5

Maybe a stupid question, but:
Why not configure the scanner in order to send scanned data to the keyboard buffer? This way, the scanner works exactly as when the data would have been entered by keyboards.
Regards
Thomas

JackEoh

ta5 wrote:

Maybe a stupid question, but:
Why not configure the scanner in order to send scanned data to the keyboard buffer? This way, the scanner works exactly as when the data would have been entered by keyboards.
Regards
Thomas

It would be ideal, but I have to work with the current handheld spec, can't modify the handheld software!