Bulk SMS using MSCOMM

[vkssms]

I am developing a SMS based application using VB 6.0. In a particular module I have send a single message to several persons using GSM Modem, I am using the following code:

mscomm1.output = AT+CMGS='9880699876' & chr$(13)
mscomm1.output=AT+CMGS='Message' & chr$(26) ' Ctrl+Z character

the message is received by the receipent 10 out of 10 times

However if I am sending the same thing to many users like this

do while not adorsd.eof ' recordset getting mobile number from database
mscomm1.output = AT+CMGS=adorsd.fields(i).value & chr$(13) ' getting stored numbers from a database.
mscomm1.output=AT+CMGS='Message' & chr$(26) ' Ctrl+Z character
adorsd.movenext
loop

ONly the first recepient is getting the message

somebody suggested Sleep API but I don't have 100% success although inbetween some of the receipients are getting the message.

Can somebody suggest some way.

thanks!!!
venkat

[Ron Weller]

First you need an OnComm event handler. This captures incomming replys from the mscomm control. After sending the first line you should wait for a response of the '>' character or some other response like an 'Error', or if no response comes after say 50 seconds, then consider it a timeout.
If you do get the '>' character then send the second part, the message. For this part you should be waiting for the text 'OK' rather than the '>' character. Otherwise it was not successful. You should always be checking for timeout on every send.
Once you have the 'OK' response then you can start over with the next message.
In your OnComm event code you should keep capturing input so long as the mscomm controls InBufferCount is >0. As you capture the input and add it to your input buffer string, check for special characters vbCr, vbLf, and '>'. These you do not want to add to the input buffer string. you can set a flag if the character is '>' so your send routine can check the flag, to see when it becomes True. And Once you hit a vbCr you have a processable line of text that you can check for the 'OK' string or scan it for the 'error' string to see if you got any errors or anything else unexpected.

[vkssms]

How to send bulk SMS?
thanks ron weller !!!

I solved it like this.
do while not adorsd.eof ' recordset getting mobile number from database
mscomm1.output = AT+CMGS=adorsd.fields(i).value & chr$(13)
' getting stored numbers from a database.
mscomm1.output=AT+CMGS='Message' & chr$(26) ' Ctrl+Z character
adorsd.movenext
loop

do
do events
rcvBuffer=rcvBuffer+MSCOMM1.input
loop until Instr(rcvBuffer,"+CMGS:") or inster(rcvBuffer,"ERROR")

Is it oK? On yesterday's test (05/15/07) I had 100% success on 5 mobile numbers. I will try today with more numbers like 25, 50 etc. and come back to you.

bye
have nice day!!!

[vkssms]

I solved the problem by waiting for +CMGS: in the buffer and It is very successfull. I have tested several times and all the messages are sent. But, the average time is 5 secs for each SMS.

Shall I try waiting for the second ">" character (after the first one) and then come out of the loop like

MSCOMM1.output= "AT+CMGS=" & Mobile Number & chr$(13)
do
do events
rcvbuffer=rcvbuffer+mscomm1.input
loop until instr(rcvbuffer,">")

position=instr(rcvbuffer,">")

do
do events
rcvbuffer=rcvbuffer+mscomm1.input
loop until instr(position+1,rcvbuffer,">")

Can this be taken as confirmation isntead of "+cmgs:"
Will the duration be reduced say by 1 or 2 seconds. Pl. clarify

reg
venkat

[Ron Weller]

More like this:

Private bGr As Boolean
Private bOK As Boolean
Private bErr As Boolean
Private bRing As Boolean

Private Sub mscomm1_OnComm()
  Static stEvent     As String
  Dim stComChar      As String * 1

  Select Case MSComm1.CommEvent
  Case comEvReceive
    Do
      stComChar = MSComm1.Input
      Select Case stComChar
      Case ">"
        bGr = True
      Case vbLf  'ignore linefeeds
      Case vbCr
        'Carriage Return so process incoming string
        If Len(stEvent) > 0 Then
          Select Case Left(stEvent, 5)
          Case "OK", "+CMTI"
            bOK = True
          Case "ERROR"
            bError = True
          Case "RING"
            'MsgBox "Incoming Call Alert", vbInformation
            bRing = True
          End Select

          stEvent = ""
        End If
      Case Else
        stEvent = stEvent + stComChar
      End Select
    Loop While MSComm1.InBufferCount
  Case comEvCTS
    MsgBox "Modem Unplugged", vbInformation
  End Select

End Sub

[vkssms]

Thanx weller. Nice answer. But what about the time saving factor will it reduce one or two seconds as compared to 5 secs avg.

reg
venkat

[Ron Weller]

I have absolutly no idea if it will or not. I don't know if it is a bad communications line, i.e. a hardware issue, or if it is because you are causing the delay by not responding correctly to each message that you send. The thing is that if you process all of the inbound responses as they come in, it should reduce any delays that might be caused by ignoring the inbound response's. All communications are a two way street. You send a message you get back a response. If you don't at least empty the input buffer, even if you ignore what's in it, their could be delays as you wait for the incomming message to timeout, so that you can send the next message.
One thing you can do is log everything to a log file, run a bunch of tests and see what you get. Everytime you send a message write what you sent to the log file, also every time you get a response back write it to the log file. When you write to the log file include the current date and time this way you can see what you sent, what the response was, and how long it took between each step. If there is a big delay, then maybe it is because the response that you got before you sent the next message, required a specific message back and because you did not send it, it kept waiting until it timed out. Look for situations like this and you can reduce the delay between each message.

[harlove]

Hello every one
my name is harlove
i have the related code implemantation of SMS server which send , receive,store or interact with database ,respond in response to an incoming msg , i want to sale this software ,i am also have lots of idea like How we use SMS application with different different way and different field ,

thanks

harlove

[Ron Weller]

Example of Bulk SMS
http://www.pscode.com/vb/scripts/Sho...57670&lngWId=1

[vkssms]

Thanks once again! weller.

Client is not worried about the time. I want to freeze the software. I will proceed like this

SendMessageUsers:
MScomm1.output="AT+CMGS=" & Mobile Number & Chr$(13)

do
do events
rcvBuffer=rcvBuffer+mscomm1.input
loop until instr(rcvbuffer,">")

MScomm1.output="AT+CMGS=" & Message & Chr$(26)

do
do events
rcvBuffer=rcvBuffer+mscomm1.input
loop until instr(rcvbuffer,"+cmgs:") or instr(rcvbuffer,"ERROR")

' I have come across only these two above situations.

if instr(rcvbuffer,"ERROR") then
HintLabel="Message not Sent" ' Hint label shows activities
GOTO SendMessageUsers ' Call Routine Again for next user
end if

Anything else should i add.

regards
venkat

[Ron Weller]

You might also want to check the InBufferCount, which will indicate if there is any thing else in the input buffer. You can also clear the input buffer by setting this to Zero or just by reading the data with Input.

[vkssms]

thanks weller. This module is working OK.
Now one more problem. I had created a datareport (5 reports) using DataEnivornment designer which was working fine. However, now I am getting the message "Invalid Data Source". After analysis I found that DataEnvironment designer is not working even while accessing records with the database using the connection.

Any suggestions please.

Thanx!

[insurbitzu]

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edit by admin: Feel stupid now Mr. Spammer? Go with the feeling!

[vkssms]

Hai Wuller

I have finished the project and I want to make EXE file now. I made a exe file and using package and deployment wizard. It is working fine in the same machine. However, when I installed in another machine I could not install and it hanged and could never install.

I could however work with the EXE when copying all the required files in the directory. I found out that Only reports created by data reports were not working (Runtime error recd) I had not copied three report files (will try today) and the related DataEnviornment designer.

My question is:
1. why messages where not received while running the SetUP file when there was a failure in installation so that these could be set right.

2. I also found that Data Access Components Installed. Is it required?

Throw some light.

reg
venkat