comm port programming

[al]

Hi,

I am creating an application in access 97, so coding in vba. I am at
the stage of sending values to my external machine, but am stuck at a
point.

I need to send each character at an interval of 0.1 seconds.

So using the timer_event, i have set the timerinterval to 100.

Now what i need to know is how i can actually use this in a loop so
that it will repeat the function of send every 0.1 seconds.

i am having trouble with calculating how many charcaters are in the
string i'm sending, and thus not knowing how many times to loop through
the send code.

I know this may sound like nonsense, heres some code to help show what
i'm trying to achieve.

Option Compare Database
Option Explicit
Public sBuffer As String
'************** *************** *************** *************** *************** *******
'TESTS TO PERFORM DURING TESTING PHASE

'Insulation Resistance - Voltage (500v dc) Resistance (2 M ohms) Time
(2 secs)
' strTest = Chr$(64) & Chr$(231) & Chr$(18) & "I" & Chr$(0) &
Chr$(5) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(2) & Chr$(0) &
Chr$(0) & Chr$(2) & Chr$(0) & Chr$(0) & Chr$(1) & Chr$(1) & Chr$(9) &
Chr$(9) & Chr$(9) & Chr$(9)
'Load Functional testing - Voltage (240v) Time (5 secs) Current Range
(0.5 to 13A)
' strTest = Chr$(64) & Chr$(231) & Chr$(18) & "R" & Chr$(1) &
Chr$(0) & Chr$(115) & Chr$(100) & Chr$(0) & Chr$(170) & Chr$(170) &
Chr$(240) & Chr$(0) & Chr$(1) & Chr$(0) & Chr$(220) & Chr$(5) & Chr$(4)
'AC Flash - Voltage (1000v ac) Trip Current (10 mA) Ramp UP (1 secs)
Peak Hold (1 secs) Ramp Down (0.5 secs)
' strTest = Chr$(64) & Chr$(231) & Chr$(13) & "A" & "B" & "t" &
Chr$(232) & Chr$(3) & Chr$(160) & Chr$(0) & Chr$(1) & Chr$(0) &
Chr$(160) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(10) & Chr$(0)
'Earth/Ground Continuity - Current (25 A) Upper (0.5 ohms) Time (2
secs)
' strTest = Chr$(64) & Chr$(231) & Chr$(9) & "E" & Chr$(25) &
Chr$(0) & Chr$(2) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(100) & Chr$(0)
'Phase Neutral Continuity - Upper(100 ohms) Lower (5 ohms) Time (1
secs)
'strTest = Chr$(64) & Chr$(231) & Chr$(12) & "P" & Chr$(0) &
Chr$(0) & Chr$(1) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(5) & Chr$(0) &
Chr$(1) & Chr$(0) & Chr$(0)
'************** *************** *************** *************** *************** **********

Private Sub cmdConnect_Clic k()
' open comms port
'mscomm1.CommPo rt = 1 'control is using COM1
'mscomm1.Settin gs = "9600,n,8,1 " 'set up the port parameters
'mscomm1.RThres hold = 1 'set the oncomm event to trigger whenever data
arrives
'mscomm1.PortOp en = True 'open the port
End Sub

Private Sub cmdRemote_Click ()
' obtain remote control of Elite 2
Dim strTest As String
strTest = Chr$(64) & Chr$(224) & Chr$(0)
mscomm1.Output = strTest
End Sub

Private Sub cmdSend_Click()
' send test values as required
Dim strTest As String
'EarthBond from manual
strTest = Chr$(64) & Chr$(231) & Chr$(9) & "E" & Chr$(24) & Chr$(0)
& Chr$(0) & Chr$(12) & Chr$(0) & Chr$(10) & Chr$(0) & Chr$(100) &
Chr$(0)
mscomm1.Output = strTest

'*** WE ARE RECEIVING NO RESPONSE HERE, REGARDLESS OF WHICH TEST WE
SEND ***
End Sub

Private Sub cmdStatus_Click ()
' request status of Elite 2
Dim strTest As String
strTest = Chr$(64) & Chr$(228) & Chr$(0)
mscomm1.Output = strTest
End Sub
Private Sub cmdClose_Click( )
' close connection
mscomm1.PortOpe n = False
End Sub

Private Sub cmdLocal_Click( )
' switch to local control of Elite 2
Dim strTest As String
strTest = Chr$(64) & Chr$(237) & Chr$(0)
mscomm1.Output = strTest
End Sub
Private Sub Form_Load()

'will set the timer for 0.1 seconds
'Me.TimerInterv al = 100

End Sub

Private Sub Mscomm1_OnComm( )
' responses from Elite 2 pushed to textbox
If mscomm1.CommEve nt = NETComm_EV_RECE IVE Then

'call timer
End If
End Sub

Private Sub Form_Timer()

'check to see how many characters are in strTest

'if strTest is minus the original count but doesn't = 0
If strTest = strTest - 1 And Not Null Then

'send the next chr
'sBuffer = sBuffer & mscomm1.InputDa ta
MsgBox "received"
'txtOutput = sBuffer
'sBuffer = ""
'Me.TimerInterv al = 0
End Sub

Any help on how timer intervals work and ideas on how i can send data
through the comm port is very much apreciated,

Many thanks,

Alex

[Salad]

al wrote:

Hi,

I am creating an application in access 97, so coding in vba. I am at
the stage of sending values to my external machine, but am stuck at a
point.

I need to send each character at an interval of 0.1 seconds.

So using the timer_event, i have set the timerinterval to 100.

Now what i need to know is how i can actually use this in a loop so
that it will repeat the function of send every 0.1 seconds.

i am having trouble with calculating how many charcaters are in the
string i'm sending, and thus not knowing how many times to loop through
the send code.

I know this may sound like nonsense, heres some code to help show what
i'm trying to achieve.

Option Compare Database
Option Explicit
Public sBuffer As String
'************** *************** *************** *************** *************** *******
'TESTS TO PERFORM DURING TESTING PHASE

'Insulation Resistance - Voltage (500v dc) Resistance (2 M ohms) Time
(2 secs)
' strTest = Chr$(64) & Chr$(231) & Chr$(18) & "I" & Chr$(0) &
Chr$(5) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(2) & Chr$(0) &
Chr$(0) & Chr$(2) & Chr$(0) & Chr$(0) & Chr$(1) & Chr$(1) & Chr$(9) &
Chr$(9) & Chr$(9) & Chr$(9)
'Load Functional testing - Voltage (240v) Time (5 secs) Current Range
(0.5 to 13A)
' strTest = Chr$(64) & Chr$(231) & Chr$(18) & "R" & Chr$(1) &
Chr$(0) & Chr$(115) & Chr$(100) & Chr$(0) & Chr$(170) & Chr$(170) &
Chr$(240) & Chr$(0) & Chr$(1) & Chr$(0) & Chr$(220) & Chr$(5) & Chr$(4)
'AC Flash - Voltage (1000v ac) Trip Current (10 mA) Ramp UP (1 secs)
Peak Hold (1 secs) Ramp Down (0.5 secs)
' strTest = Chr$(64) & Chr$(231) & Chr$(13) & "A" & "B" & "t" &
Chr$(232) & Chr$(3) & Chr$(160) & Chr$(0) & Chr$(1) & Chr$(0) &
Chr$(160) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(10) & Chr$(0)
'Earth/Ground Continuity - Current (25 A) Upper (0.5 ohms) Time (2
secs)
' strTest = Chr$(64) & Chr$(231) & Chr$(9) & "E" & Chr$(25) &
Chr$(0) & Chr$(2) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(100) & Chr$(0)
'Phase Neutral Continuity - Upper(100 ohms) Lower (5 ohms) Time (1
secs)
'strTest = Chr$(64) & Chr$(231) & Chr$(12) & "P" & Chr$(0) &
Chr$(0) & Chr$(1) & Chr$(0) & Chr$(0) & Chr$(0) & Chr$(5) & Chr$(0) &
Chr$(1) & Chr$(0) & Chr$(0)
'************** *************** *************** *************** *************** **********

Private Sub cmdConnect_Clic k()
' open comms port
'mscomm1.CommPo rt = 1 'control is using COM1
'mscomm1.Settin gs = "9600,n,8,1 " 'set up the port parameters
'mscomm1.RThres hold = 1 'set the oncomm event to trigger whenever data
arrives
'mscomm1.PortOp en = True 'open the port
End Sub

Private Sub cmdRemote_Click ()
' obtain remote control of Elite 2
Dim strTest As String
strTest = Chr$(64) & Chr$(224) & Chr$(0)
mscomm1.Output = strTest
End Sub

Private Sub cmdSend_Click()
' send test values as required
Dim strTest As String
'EarthBond from manual
strTest = Chr$(64) & Chr$(231) & Chr$(9) & "E" & Chr$(24) & Chr$(0)
& Chr$(0) & Chr$(12) & Chr$(0) & Chr$(10) & Chr$(0) & Chr$(100) &
Chr$(0)
mscomm1.Output = strTest

'*** WE ARE RECEIVING NO RESPONSE HERE, REGARDLESS OF WHICH TEST WE
SEND ***
End Sub

Private Sub cmdStatus_Click ()
' request status of Elite 2
Dim strTest As String
strTest = Chr$(64) & Chr$(228) & Chr$(0)
mscomm1.Output = strTest
End Sub
Private Sub cmdClose_Click( )
' close connection
mscomm1.PortOpe n = False
End Sub

Private Sub cmdLocal_Click( )
' switch to local control of Elite 2
Dim strTest As String
strTest = Chr$(64) & Chr$(237) & Chr$(0)
mscomm1.Output = strTest
End Sub
Private Sub Form_Load()

'will set the timer for 0.1 seconds
'Me.TimerInterv al = 100

End Sub

Private Sub Mscomm1_OnComm( )
' responses from Elite 2 pushed to textbox
If mscomm1.CommEve nt = NETComm_EV_RECE IVE Then

'call timer
End If
End Sub

Private Sub Form_Timer()

'check to see how many characters are in strTest

'if strTest is minus the original count but doesn't = 0
If strTest = strTest - 1 And Not Null Then

'send the next chr
'sBuffer = sBuffer & mscomm1.InputDa ta
MsgBox "received"
'txtOutput = sBuffer
'sBuffer = ""
'Me.TimerInterv al = 0
End Sub

Any help on how timer intervals work and ideas on how i can send data
through the comm port is very much apreciated,

Many thanks,

Alex

I'm not going to bother getting into your code, however you should be
able to understand this concept well enough that you can use it or
discard it.

You could create 2 fields. One field holds the string (HoldString).
The second field holds the counter (HoldCounter). Set the visible
property of both to False (hidden)

A command button is pressed, or an event is fired. When fired, create a
string. Next, set the value to 1 in the counter field (HoldCounter) and
store the string to the field (HoldString). Now set the timer interval
to whatever.

In the OnTime event send the character of the string. Ex:
Dim strToSend As String
strToSend = Mid(Me.HoldStri ng,Me.HoldCount er,1)
...send or do whatever to the character in StrToSend
If Me.HoldCounter < Len(Me.HoldStri ng) Then
Me.HoldCounter = Me.HoldCounter + 1
Else
Me.TimerInterva l = 0
Endif

I only close the timer when all of the chars have been processed and passed.

[Albert D. Kallal]

I don't think you need to use the forms timer event at all..

You got this event firing all the time..and you have some coding running.
This kind of makes controlling things a bit hard, as to "when" does the next
timer event occur.

I would try a simple approach first (remember the Kiss principle!!).

All you got is a string, and want to send one character..and then wait .1 of
a second..

Lets dump all this complex timer stuff...

Just build a function/loop that sends one char..and then waits ..1....

This approach is dead simple....

dim i as interger
dim strSomeString as string

strSomeString = "bla bla bal"

for i = 1 to len(strSomeSstr ing)

mscomm1.Output = mid(strSomeStri ng,i,1)
Call sSleep(100)

next i

All you need is a sleep function that pauses the code. ...
You can find one here:
http://www.mvps.org/access/api/api0021.htm

You might also consider putting a doevents into the loop to yield
processing. I would try the above..and also a loop with DoEvents...

Further, you can just make the above a nice function..and use it anywhere in
your code..
SendMyDelayData strData1
SendMyDelayData strData2

etc. etc.

This makes coding much easier also...
--
Albert D. Kallal (Access MVP)
Edmonton, Alberta Canada
pl************* ****@msn.com
http://www.attcanada.net/~kallal.msn

[al]

Albert,

i like this way of doing things! I am quite new to access and
programming so have not had much experience as yet, i'm wondering if
you coulkd help me furthur?

I have got the string to send and the counter is working so it counts
every second until it has reached the end of the string.

Now, for pure testing purposes, is it possible to show me how to send
the string at that second at a time, so the a textbox is updated every
second to simulate what it would be like going out of the comm port? I
just want to see the string filtering through and updating a
textbox(txtOutp ut), then i'll know how to send it via comm once i can
do it in the same way to a textbox.
Thanks gratefully for your help,

Alex