Problem with AT send with GSM modem

**willakawill** · Jan 30 '07, 12:35 AM

Hi. You could try this

Code:

Const quote As String = """"
MsComm.Output = "AT+CMGS=" & quote & "+351nnnnnnnnn" & quote & vbCr

**Killer42** · Jan 30 '07, 01:49 AM

Originally posted by UmDois

I have a GSM modem, Wavecom.
When I connect to it using HyperTerminal, i can send SMS with the standard AT comands, like this:
AT+CMGS="+351nn nnnnnnn" <CR>
> text to send in the message <Control-Z>
and the SMS goes on.
When I use VisualBasic, the SAME AT sequence does not work.
And I get an ERROR (twice).
The manual says to do the following:
MSComm.Output = "AT+CMGS=" & chr(34) & "+ "+351nnnnnn nnn" & chr(34) & chr(13)
MsComm.Output = "text to send in the message" & chr(26).

A couple of questions...

Are you certain that it's only a CR which is sent after the AT command?
What error are you getting?
What does the ">" represent on the second line? (I ask mainly because it is not present in the VB version.)
Are you sure you're in command mode? I seem to recall (from more than 10 years ago, I think) that you have to pause for at least a second, then send "+++" then another pause, to go into command mode. But this probably only applies if you are online at the time, right?
Is this code copied/pasted, or typed in here? Because
MSComm.Output = "AT+CMGS=" & chr(34) & "+ "+351nnnnnn nnn" & chr(34) & chr(13)
seems to have quotes in the wrong places. It probably should have been
MSComm.Output = "AT+CMGS=" & chr(34) & "+351nnnnnn nnn" & chr(34) & chr(13)

You can also make the code much more compact and readable by using CONST values as willakawill suggested. (Oops! Didn't realise you'd also fixed the mixed-up quotes, Will.)

**willakawill** · Jan 30 '07, 04:13 AM

Yeah. Get with it down there. You're supposed to be 13 hours ahead of me :)

**iburyak** · Jan 30 '07, 05:12 AM

It looks like your error is here:

[PHP]"+ "+351nnnnnn nnn" [/PHP]

You have "+ twice.

**iburyak** · Jan 30 '07, 05:19 AM

Try this:

MSComm.Output = "AT+CMGS=""+351 nnnnnnnnn""" & chr(13)

MsComm.Output = "text to send in the message" & chr(26).

**willakawill** · Jan 30 '07, 06:15 AM

Originally posted by iburyak

Try this:

MSComm.Output = "AT+CMGS=""+351 nnnnnnnnn""" & chr(13)

MsComm.Output = "text to send in the message" & chr(26).

You are posting the same answer that has already been posted by 2 others

**Killer42** · Jan 30 '07, 08:05 PM

Originally posted by willakawill

Yeah. Get with it down there. You're supposed to be 13 hours ahead of me :)

Yeah, well it's hard to forecast accurately what someone is going to say in 13 hours. ;)

**sirsnorklingtayo** · Jan 31 '07, 07:51 AM

Originally posted by UmDois

I have a GSM modem, Wavecom.
When I connect to it using HyperTerminal, i can send SMS with the standard AT comands, like this:

AT+CMGS="+351nn nnnnnnn" <CR>
> text to send in the message <Control-Z>

and the SMS goes on.

Note: <CR> means ENTER
Note: <CR> is ASCII 13, and Control-Z is ASCII 26.

When I use VisualBasic, the SAME AT sequence does not work.
And I get an ERROR (twice).

The manual says to do the following:

MSComm.Output = "AT+CMGS=" & chr(34) & "+ "+351nnnnnn nnn" & chr(34) & chr(13)

MsComm.Output = "text to send in the message" & chr(26).

Note: chr(34) is the character for the commas(").

What is wrong?

Many thanks for any help.

Hi friend,

I've been in that kind of situation before and I used VB6 too, I developed a computer program that will keep all the SMS to my database and reply back with some information.

Ok here is the answer, before i tried that using chr(13) because this is the equivalent for the new line but unfortunately i dont know why this chr(13) is not working in MSCOM, but the only thing left is the constant value of VBCRLF you can use this as a substitute in chr(13)

Inshort

chr(13) = VBCRLF

and dont forget to send +++ it means that you will set the GSM in Command mode. Some1 already post this one, you better be careful in sending AT Command always keep in mind that before sending another batch of command you need to wait just for a second or 2, just use Sleep function in VB6.

Actually, after I solved that problem reagrading GSM and MSCOMM I realized that ANSI C is the much better language to use beacuse it is very easy to communicate with Devices like GSM. I am just telling you this because I experienced that before, but it will work fine in VB6 with MSCOMM

Norman

**sirsnorklingtayo** · Jan 31 '07, 08:50 AM

Originally posted by sirsnorklingtay o

Hi friend,

I've been in that kind of situation before and I used VB6 too, I developed a computer program that will keep all the SMS to my database and reply back with some information.

Ok here is the answer, before i tried that using chr(13) because this is the equivalent for the new line but unfortunately i dont know why this chr(13) is not working in MSCOM, but the only thing left is the constant value of VBCRLF you can use this as a substitute in chr(13)

Inshort

chr(13) = VBCRLF

and dont forget to send +++ it means that you will set the GSM in Command mode. Some1 already post this one, you better be careful in sending AT Command always keep in mind that before sending another batch of command you need to wait just for a second or 2, just use Sleep function in VB6.

Actually, after I solved that problem reagrading GSM and MSCOMM I realized that ANSI C is the much better language to use beacuse it is very easy to communicate with Devices like GSM. I am just telling you this because I experienced that before, but it will work fine in VB6 with MSCOMM

Norman

EXAMPLE:

Code:

Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)


Private Sub Command1_Click()
Dim strSMS As String
'set contact number
'buffer you message here
strSMS = "Hello World!"
'Before sending command
MSComm1.Output = "+++" & vbCrLf
'wait a second
Sleep 1
'send at commands
MSComm1.Output = "AT+CMGS=" & Chr(34) & "+351nnnnnnnnn" & Chr(34) & vbCrLf

'There are some GSM modems that after sending "AT+CMGS"
'it will response before buffering the message

'Ex.
' step 1: MSComm1.Output = "AT+CMGS=" & Chr(34) & "+351nnnnnnnnn" & Chr(34) & vbCrLf
' step 2: MSComm1.Input is equal to OK/ERROR
' step 3: then > insert your message

'In this case the GSM is allowing you to check first if the AT command is valid or not
'before buffering the message to GSM

'I dont know if this is your case but you can check.

While 1
    'wait for 1 second or 2
    
    Sleep 1  'this is depend on how fast your GSM communicate with MSCOMM
    
    'Always wait this > sign to come out, because this the signal that the GSM is ready
    'to get the Message
    
    'if MSComm1.Input = ">" send your Message to GSM
    
    'note: make it sure that no other chr(s) in MSComm1.Input except ">"
    'The last thing to remember is do not ever try to use the DOEVENTS
    
    If StrComp(Left(MSComm1.Input, 1), ">", vbBinaryCompare) = 0 Then
        MSComm1.Output = strSMS & Chr(26)
        Sleep 2
        'Before you do this pls remove the chr(26)
        If StrComp(Replace(MSComm1.Input, Chr(26), ""), "OK", vbBinaryCompare) = 0 Then
            'place your flag
            GoTo ExitWhile
        ElseIf StrComp(Replace(MSComm1.Input, Chr(26), ""), "ERROR", vbBinaryCompare) = 0 Then
            'place your flag
            GoTo ExitWhile
        Else
    End If
Wend

ExitWhile:
    'do your valdations here etc
    'Check your falg here if error is true or false
    Sleep 2
    

End Sub

**sirsnorklingtayo** · Jan 31 '07, 09:00 AM

Originally posted by sirsnorklingtay o

EXAMPLE:

Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub Command1_Click( )
Dim strSMS As String
'set contact number
'buffer you message here
strSMS = "Hello World!"
'Before sending command
MSComm1.Output = "+++" & vbCrLf
'wait a second
Sleep 1
'send at commands
MSComm1.Output = "AT+CMGS=" & Chr(34) & "+351nnnnnn nnn" & Chr(34) & vbCrLf

'There are some GSM modems that after sending "AT+CMGS"
'it will response before buffering the message

'Ex.
' step 1: MSComm1.Output = "AT+CMGS=" & Chr(34) & "+351nnnnnn nnn" & Chr(34) & vbCrLf
' step 2: MSComm1.Input is equal to OK/ERROR
' step 3: then > insert your message

'In this case the GSM is allowing you to check first if the AT command is valid or not
'before buffering the message to GSM

'I dont know if this is your case but you can check.

While 1
'wait for 1 second or 2

Sleep 1 'this is depend on how fast your GSM communicate with MSCOMM

'Always wait this > sign to come out, because this the signal that the GSM is ready
'to get the Message

'if MSComm1.Input = ">" send your Message to GSM

'note: make it sure that no other chr(s) in MSComm1.Input except ">"
'The last thing to remember is do not ever try to use the DOEVENTS

If StrComp(Left(MS Comm1.Input, 1), ">", vbBinaryCompare ) = 0 Then
MSComm1.Output = strSMS & Chr(26)
Sleep 2
'Before you do this pls remove the chr(26)
If StrComp(Replace (MSComm1.Input, Chr(26), ""), "OK", vbBinaryCompare ) = 0 Then
'place your flag
GoTo ExitWhile
ElseIf StrComp(Replace (MSComm1.Input, Chr(26), ""), "ERROR", vbBinaryCompare ) = 0 Then
'place your flag
GoTo ExitWhile
Else
End If
Wend

ExitWhile:
'do your valdations here etc
'Check your falg here if error is true or false
Sleep 2

End Sub

In addition, please always use PDU mode in reading and sending TEXT SMS Messages.

MSComm1.Output = "AT+CMGS=0"

AT+CMGF: Message Format:
Command Possible response(s) +CMGF=[<mode>] +CMGF?+CMGF: <mode> +CMGF=?+CMGF: (list of supported <mode>s)
<mode>: 0: PDU mode;
<mode>: 1: TEXT mode;

check out about PDU encryption/Decryption methods

IIS 10.0 Detailed Error - 404.0 - Not Found

http://www.activexperts.com/activsms/sms/pdu/

**Killer42** · Jan 31 '07, 08:40 PM

[QUOTE=sirsnorkl ingtayo]

Code:

...
    'wait for 1 second or 2
    [B]Sleep[/B] 1
...

Is this a routine of your own? I don't think VB6 has a Sleep statement. Mine doesn't, anyway.

**sirsnorklingtayo** · Feb 1 '07, 01:40 PM

[QUOTE=Killer42]

Originally posted by sirsnorklingtay o

Code:

...
    'wait for 1 second or 2
    [B]Sleep[/B] 1
...

Is this a routine of your own? I don't think VB6 has a Sleep statement. Mine doesn't, anyway.

Nop, SLEEP is an WIN32 API function it acts like a delay() function in ANSI C

Here is the declaration:

Code:

'You can place this in Form, Module Class etc but indicate the declration scope
'like Global,Public,Private

Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

'to use this

Private Sub StopForAWhile(byval milliseconds as Integer)

  Sleep 1000 ' stop for 1 second

end sub

and I admit that I made a mistake instead of Sleep 1 it should be Sleep 1000

Sleep 1 = 1/1000 second stop
Sleep 1000 = 1second stop

Sorry for my mistakes

hehehe

norman

**Killer42** · Feb 1 '07, 10:28 PM

Originally posted by sirsnorklingtay o

Nop, SLEEP is an WIN32 API function it acts like a delay() function in ANSI C

Ah! Thanks for the reminder. I think I used it, years ago.

**willakawill** · Feb 1 '07, 10:34 PM

In the interests of clarity for those scouring these pages for tidbits, perhaps you mean:

Code:

Private Sub StopForAWhile(byval milliseconds as Integer)

Sleep milliseconds ' stop for (milliseconds/1000) seconds

end sub

This is also a useful way to call sleep:

Code:

Private Sub WaitSec(ByVal secs as Integer)

Sleep secs * 1000 ' stop for secs seconds

end sub

Problem with AT send with GSM modem

Problem with AT send with GSM modem

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