Solved

How to use a coin acceptor in VB

Posted on 2001-06-19
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1,417 Views
Last Modified: 2010-05-02
I'm now working with a coin acceptor and the comm port.

Using this code i'm able to reciebe the pulses of the acceptor.

Private Sub MSComm1_OnComm()
    Select Case MSComm1.CommEvent
        Case comEvCD  
        msgbox "Pulse"

    End Select
end sub

but it fails with some pulses and don't works at 100% and i have to achieve that every pulse sent by the acceptor is triggered by my program.

I am using this code to initialize the serial port:
   
MSComm1.CommPort = 2
MSComm1.InputLen = 0
MSComm1.Handshaking = comNone
MSComm1.PortOpen = True

I need help about what are the correct parameters to program the Mscomm to receive/send pulses to the acceptor.

I have NO idea about comm programmming and i'm actualing searching info about that :)

Thanks in advance
0
Comment
Question by:MoriQuendi
11 Comments
 
LVL 5

Accepted Solution

by:
gbaren earned 300 total points
Comment Utility
Mori,

Without handshaking, the events are not reliable. The device you are working with, probably does not support handshaking anyway.

The way to do this is to keep polling the InBufferCount property. When it becomes > 0, that means you had received that many pulses. You access the Input property to clear InBufferCount back to 0.

This should be done in a Timer control's Timer event.


Here's some code to try:


------------------------------------------------
Option Explicit

Private Sub Form_Load()
   
    With MSComm1
        .CommPort = 1
        .Settings = "9600,n,8,1"
        .PortOpen = True
    End With
   
    With Timer1
        .Interval = 100 'poll every 100 milliseconds
        .Enabled = True
    End With
   
End Sub

Private Sub Timer1_Timer()

    Timer1.Enabled = False

    If MSComm1.InBufferCount > 0 Then
        MsgBox "Pulse with data: " & MSComm1.Input
    End If
       
    Timer1.Enabled = True

End Sub

---------------------------------------------------
0
 

Author Comment

by:MoriQuendi
Comment Utility
Do you think is better to use a timer instead the OnComm event?

well i'll try :)
0
 

Author Comment

by:MoriQuendi
Comment Utility
Do you think is better to use a timer instead the OnComm event?

well i'll try :)
0
 
LVL 5

Expert Comment

by:gbaren
Comment Utility
If the OnComm event was more reliable, it would be better to use it. As it is, unfortunately, this is the best way. The MSComm control's OnComm event has never been reliable.
0
 
LVL 3

Expert Comment

by:kfrick
Comment Utility
I'd start looking at your hardware....the Comm port wants to see about +9 to +12 VDC as an "OFF" signal, and about -9 to -12 VDC as an "ON" signal. You might need to convert some voltage levels to improve the reliability.

I have been using the MSComm control in numerous projects for the last 6 years, and have not run into an OnEvents problem.

Hope this helps!
-kf
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Author Comment

by:MoriQuendi
Comment Utility
The coin acceptor is manufactured by Jofemar and works with 12V (i'm plugging the acceptor to the computer's power supply directly).

Is there any Comm propertie to take care about? or the default ones works with this device?
0
 

Author Comment

by:MoriQuendi
Comment Utility
Sorry, i was out for two weeks ad i was unable to continue this task, expect my answer soon ;)
0
 
LVL 5

Expert Comment

by:gbaren
Comment Utility
Actually, are you sure this is a serial device? Sorry for the silly question, I just want to make sure you have a serial and not a contact closure device.
0
 

Author Comment

by:MoriQuendi
Comment Utility
This device is not originally developed to be attached to a computer but it have to work.

It seems that it can be a hardware solution:

http://www.cyberzeus.demon.co.uk/page1.htm

There's a device than check when the serial is working or not.


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LVL 49

Expert Comment

by:DanRollins
Comment Utility
Hi MoriQuendi,
It appears that you have forgotten this question. I will ask Community Support to close it unless you finalize it within 7 days. I will suggest to:

    Split points between: gbaren and kfrick

MoriQuendi, if you think your question was not answered at all or if you need help, you can simply post a new comment here.  Community Support moderators will follow up.

EXPERTS: If you disagree with that recommendation, please post an explanatory comment.
==========
DanRollins -- EE database cleanup volunteer
0
 

Author Comment

by:MoriQuendi
Comment Utility
I forgot this thread at all, sorry.
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