Com Port with mscomm32.ocx

frytach

Need help with reading data (Barcodescanner) from a com port. I'm using the mscomm32.ocx. (Navision 370)

Example:
//init
MSComm.CommPort(4); //COM4
MSComm.Settings('9600,N,8,1'); //Parameter
MSComm.InputLen(0); //Sofort senden
MSComm.InBufferCount(0); //Init
MSComm.InputMode(0); //Textmode
MSComm.PortOpen(TRUE); //öffnen

//Read????
Result := MSComm.Input();

Doesn't work.
I tried the nfcomm.ocx before. Doesn't work either.
I have no experience with com port programming an would be thankful for any help (hints or examples).

The barcodescanner is working fine. No problems with hyperterminal.

kine

I never used this way of communication with Barcode scanner. I created own external application, which take the data send from COM port and send them as keystroke to system. Or it work as Automation, which can read the data from scanner and signal that new data arrived is passed to NAV through sending one hotkey and catching that hotkey through menuitem with hotkey in NAV (I had no time to create working event in the automation).

It means that primary function of the aplication is to use COM scanner as Keyboard scanner...

frytach

Hi, maybe it's possible to run in a loop and wait for an result of the scanner with a timeout or a max loop counter. But my try wasn't successful.

Has someone written an OCX or Automation for this case. Or is there any existing codeexample for the nfcomm.ocx? My try with nfcomm.ocx looks like this:

//init
CLEAR(ComPort);
ComPort.ComX := 3; //com4
ComPort.BaudRate := 6; //9600bps;
ComPort.Parity := 0; //None
ComPort.DataBits := 4; //8 databits
ComPort.DtrDsr := FALSE;
ComPort.RtsCts := FALSE;
ComPort.XonXoff := FALSE;
ComPort.StopBits := 0; //1 Stopbit
ComPort.SaveParam;

Result := ComPort.ReceiveStr;

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

frytach

=D> Super, so funktioniert es. Danke

kriki

[Topic moved from 'NAV/Navision' forum to 'NAV Tips & Tricks' forum]

Adain

Thanks very much for that great entry.