Visual Basic :: Communicating To Serial Ports With Comm Port Number Greater Than 16

REgarding Serial Port Communication With Greater Ports
Hi,
Actually i have to set serial ports greater than 16 for communication.
for that i used
There was a hack that came around about modifying the MsComm control to
access greater than 16 ports:
"In the code there is a unique sequence of three bytes, 3d 10 00. Pick a hex
editor and change the value 10 to say 7f. Now you have changed the default
value of a variable MAX_PORTS to 127. The name of the variable is arbitrary.
Save the changed file and off you go." the problem in using this was when some one reinstall the setup the ocx which we created is getting replaced by the old ocx so is there any way to replace an ocx(Mscomm32.ocx) which is being used by the project by another ocx which i has made by hacking the existing ocx and stored in the system file ,this has to replace the system ocx which is used by it at runtime .

give me other ways also for setting up communication with the higher ports

Serial Comm Ports... Silly Question.
I like very much this subject and i am already reading some guides, the problem is, the xplanations always assume so much sttuff and it is definetely not sth easy to swallow... i was thinkng... YOU the people who actually work with this sttuff in their daily routine, do you use special controls or dll components with VB to access ports and so on or you go all by yourselves... also, IF SO, (i suppose) what controls are preffered and how much do i need to know to use it (just the basics)

Communicating With Serial Port?
how can i make my application communicate with the serial port. Is there a control within VB to do this, as i seem to remember one?

If so how do i use it, and if not, how do i do this?

Thanx!

Communicating With A Serial Port
I am making a VB-program to send information to an industrial printer thru a serial port. A string variable contains the text that I want to send to the printer and I use the following code to send it:
MSComm1.Output = sText

The problem is that nothing seems to happen. The printer does not recieve anything and when I check the CommEvent it does not contain anything.

I think all settings between the program and the printer is correct but I am not completely sure. Since I have not used the MSComm before I am pretty sure that I miss something very fundamental setting or command.

Can someone please help me and give some clues?

/Nilla

Communicating With DSP Via Serial Port
Hi
For my thesis I need to communicate with a DSP (TMS320C5X from Texas Instruments).I can open and close my port, and can also low DTR (for resetting the dsp). Now I need to send a startbit to the DSP, so he can load the kernel. My problem starts here. The DSP returns me question marks. I don't know what to do. Can somebody help me please.
I'll always send source code or more information.

TNX
Viperke

Help Communicating W/ IR Device Through Serial Port
I am trying to write a VB program to input data from an IR device that connects through the serial port. I can connect to the device through Hyperterminal and download data from it (it is for connecting to thermometer dataloggers). When I try and connect through VB it doesn't seem to be communicating. Here is the code I am using:

Private Sub Form_Load()
MSComm1.CommPort = 1
MSComm1.Settings = "2400,N,8,1"
MSComm1.PortOpen = True
MSComm1.RThreshold = 1
End Sub
Private Sub CmdCancel_Click()
MSComm1.PortOpen = False
Unload Me
End Sub
Private Sub MSComm1_OnComm()
MsgBox ("input Received") 'Used to determine if the OnComm event is being triggered
Buffer$ = Buffer$ & MSComm1.Input
TxtDisplay.Text = Buffer$
End Sub

When I connect through Hyperterminal, a red light on the IR device comes on, then you just hit send on the thermometer and the data pops up on the Hyperterminal screen. I was trying to do basically the same thing with my VB program (for now, I have other plans for the data once I get this figured out). When I execute the VB program, I do not get a light on the IR device. Do I need to send it some kind of initialization string? When I hit send on the Thermometer, nothing happens, and the OnComm even is not being triggered. I don't really have any documentation on the IR device, so I am hoping someone can give me clues as to what hyperterminal is doing that I am not. Thanks.

Advice On Communicating With The Serial Port
Hi people,

I am supposed to communicate with a cashcard reader through the COM port but i have no previous experience interfacing with it.

I do not have one in my office but i am able to borrow it for two days for testing.

To maximize the two days, i hope to be more prepared. i have read up on some basic vb codes on communicating with it already.
But i do not know how can i verify whether my codes work anot..

e.g whether it received the string it should receive
Can you guys give some advice?

- I heard some people saying a DLL file of the reader, if i do get it.. how am i going to make use of that to communicate with the reader.

-if i do not get it , how am i going to communicate with the reader.. e.g. i send some trings over and can verify that it has receveived it .
very basic testing..

- what else should i look out for / other helpful advice

I need to test some basic two-way communication with it.

thanks

Advice On Communicating With The Serial Port
Hi people,

I am supposed to communicate with a cashcard reader through the COM port but i have no previous experience interfacing with it.

I do not have one in my office but i am able to borrow it for two days for testing.

To maximize the two days, i hope to be more prepared. i have read up on some basic vb codes on communicating with it already.
But i do not know how can i verify whether my codes work anot..

e.g whether it received the string it should receive
Can you guys give some advice?

- I heard some people saying a DLL file of the reader, if i do get it.. how am i going to know what functions are inside the Dll file.

-if i do not get it , how am i going to communicate with the reader.. e.g. i send some strings over and can verify that it has received it correctly.
very basic testing..

- what else should i look out for / other helpful advice

I need to test some basic two-way communication with it.

thanks

Communicating With Hardware Using Serial Port
Question in 2 sections really:

1) Does anybody know of any tutorials on sending messages through a serial port? I have heard its similar to using Winsock..

On a more techie note..

2) Basicly, the control software for my laser tag energiser boxes is old and crusty, it only runs of 486's running MS-DOS. I want to write new software supporting Windows and the like. I know exactly what the hardware is capable of, all the current possible settings and the like, I just dont know what the actuall commands are to be sent to the box down the cable. Is there a way to probe the box to get the commands or to moniter the cable as the old software sends the command and capture them?

Thanks

-GreenDaze-

Number Of Comm Ports
How can I get the number of comm ports on a computer? I want to have a settings dialog for my program that allows you to select the comm port to use for the serial communications. Is there an easy way to do this?

Number Of Comm Ports
I have as system with 20 serial ports.
I have used the comm control to access
the first 16 ports, and then used some
api functions to try using the
remaining 4 ports using ....

Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (byval lpFileName as string, byval dwDesiredAccess as Long, byval dwShareMode as Long, byval lpSecurityAttributes as Long, byval dwCreationDisposition as Long, byval dwFlagsAndAttributes as Long, byval hTemplateFile as Long) as Long
Declare Function ReadFile Lib "kernel32" (byval hFile as Long, lpBuffer as Any, byval nNumberOfBytesToRead as Long, lpNumberOfBytesRead as Long, lpOverlapped as Long) as Long
Declare Function WriteFile Lib "kernel32" (byval hFile as Long, lpBuffer as Any, byval nNumberOfBytesToWrite as Long, lpNumberOfBytesWritten as Long, lpOverlapped as Long) as Long

and so on, along with some other calls.

My problem is I can't access the ports 17-20.
The api calls work fine when I use them for ports 1 -16 and I can access ports 17-20 using hyperterminal.

Does VB not allow access to more than 16 serial ports?

Curt

Demo Programe Neede For Communicating Serial Port
Hi,
Can any one post me Demo programmes which can Explain how to communicate with Serial POst and How to send commands to Serial port,Get Respose and Display Response .......?

Best Regards.

VB Ms Comm To Control Your PC Serial Port
Hi guys, I'm really REALLY new to VB and i would like to learn more. I have been given a task to complete, and i seriously don't know where to start. I hope you guys could give me some guidance and examples.

TASK:writing simple codes in VB you can send some ‘On’ and ‘Off’ state to your serial TX output. You should be able to see some results from the MMU. You will find that the voltage would be too high and not feasible for your circuits. That is why you need a voltage translator, Max232 or SP3203EEY. The output from these devices will be within the 5V range that you can communicate it with other logic devices such as your microcontroller. Since the output from a serial port is in serial you will need a SP converter. It will convert your data to parallel form. This you will have to find out yourself what chip is able to do this. The output of this chip will then be channeled to simple LEDs to show you the display.

Ms-comm Does Not Read Data From Serial Port
Hi,

I am using Ms-comm control and polling mechanism to send and receive data from serial port. I initially thought of using timer control but that is proving to be problemetic.

High-level logic is as follows;

1. When the user presses Start button, do the required settings for ms-comm, open the port and call the routine StartPollingData.

2. This routine, StartPollingData, will send command to serial port (where a hardware device is connected) and then read the incoming data. This routine is put into endless loop to read data.

The problem I face is if no breakpoint is put on .Output method of ms-comm control, I cannot receive any data. With breakpoint, it works fine. Instead of polling mechanism, I also tried using Event driven logic. But the same problem occurs. Below is the logic i have used. Please help.

===================
Private Sub cmdStart_Click()
On Error GoTo Err_hnd

'Set Comm settings
With MSComm1.CommPort = 1

'Decide on number of characters to receive
.RThreshold = 1

'Set baud rate, parity, data bit and
'stop bit arameters
.Settings = "9600,n,8,1"

'Set/Return minimum number of chars allowable in
'transmit buffer before the MSComm control sets the
'CommEvent property to ComEvSend
'and generates the OnComm event
' .SThreshold = 4

'Open comm port
.PortOpen = True
End With

'Start Polling the Data
Call StartPollingData

Exit Sub

Err_hnd:
MsgBox Err.Description
End Sub

Private Sub StartPollingData()
Static bytSlaveID As Byte
Dim strInputData As String
Dim intNumberOfRuns As Integer
bytSlaveID = 1
Dim lngSleep
Do
'Get the Slave Data
MSComm1.Output = "S" & bytSlaveID & "R" & "E" & Chr$(13)
Do
DoEvents
strInputData = strInputData & MSComm1.Input
Loop Until InStr(strInputData, "E")
If strInputData <> "" Then
Call ProcessSlaveData(Mid$(strInputData, 2), intNumberOfRuns)
End If

bytSlaveID = bytSlaveID + 1
If bytSlaveID > 4 Then
bytSlaveID = 1
End If

Loop While True

End Sub
==================

Regards,

Vilas

How To Send File Through Serial Comm Port???
Hi all,

I want to send file through the comm port using the xmodem command in VB but VB doesn't have this command. The MSComm can't be used to send file. Is there any solution to this? Please advice.

Thanks a lot.

Regards,
Joyce

Read Data From Serial Comm Port & Display Them
i have a vb project that requires to retrieve data from serial comm port then display them. The data is a 8-bit signal eg. 10011101 so im tryin to plot this data on a bar chart.
i obtained some source code from the MSDN Library on "MsComm Control" but not certain abt its usability on my project, below is ...

MSComm Control Example
The following simple example shows basic serial communications using a modem:

Private Sub Form_Load ()
' Buffer to hold input string
Dim Instring As String
' Use COM1.
MSComm1.CommPort = 1
' 9600 baud, no parity, 8 data, and 1 stop bit.
MSComm1.Settings = "9600,N,8,1"
' Tell the control to read entire buffer when Input
' is used.
MSComm1.InputLen = 0
' Open the port.
MSComm1.PortOpen = True
' Send the attention command to the modem.
MSComm1.Output = "ATV1Q0" & Chr$(13) ' Ensure that
' the modem responds with "OK".
' Wait for data to come back to the serial port.
Do
DoEvents
Buffer$ = Buffer$ & MSComm1.Input
Loop Until InStr(Buffer$, "OK" & vbCRLF)
' Read the "OK" response data in the serial port.
' Close the serial port.
MSComm1.PortOpen = False
End Sub

InputMode Property Example
This example reads 10 bytes of binary data from the communications port and assigns it to a byte array.

Private Sub Command1_Click()
Dim Buffer as Variant
Dim Arr() as Byte

' Set and open port
MSComm1.CommPort = 1
MSComm1.PortOpen = True

' Set InputMode to read binary data
MSComm1.InputMode = comInputModeBinary

' Wait until 10 bytes are in the input buffer
Do Until MSComm1.InBufferCount < 10
DoEvents
Loop

' Store binary data in buffer
Buffer = MSComm1.Input

' Assign to byte array for processing
Arr = Buffer

End Sub

Input Property Example
This example shows how to retrieve data from the receive buffer:

Private Sub Command1_Click()
Dim InString as String
' Retrieve all available data.
MSComm1.InputLen = 0

' Check for data.
If MSComm1.InBufferCount Then
' Read data.
InString = MSComm1.Input
End If
End Sub

... i have created the bar chart but hasnt been able to display the data comin from the serial comm port so aNy HeLP is GreatLY aPpreciated!

regards,
-urbanman

Number Of Serial Ports
Can anyone tell me if there is an api call that can get the number of available serial ports on the machine that the software is running on. There has to be something because the device manager knows. I had a good link to all of the api calls on the M$ web site but lost it. Now I can't find it. if someone knows that to I would appreciate that information also.

thanks for your help.

Jason

How To Get The Number Of Serial Ports In A Computer For Mscomm Application
Hi,Gurus.How to get the Number of serial ports in a computer for mscomm application.my project is in lagging without it.plz help me

Communicating With USB Ports(VB6)
Can anyone please tell me how to communicate with a USB port?Can I use mscomm control to do it?

How To Use Comm Ports
I have a selfmade keyboard which is connected to the commport
how could i use mscomm to get the commands from the board?

Comm Ports
Just a quick question!
Is the use of comm ports and printer port to hard for a Beginner ??? I have an Eeprom Programmer that I would like to write a Windows interface for.
Thanks!!

Comm Ports
hello!

how can i close all of the comm ports on the computer using vb?

thanx

Comm Ports In W98 And W2k
Got a weird glitch in a piece of code. I'm reading data in from a comm port using MScommctrl. It is kind of a clock signal that is read in in binary and converted to a integer # and displayed. each second or so I get a new "pulse" of about 6 characters. I developed the program on a w2k machine. It works fine ... but when I migrate to a w98 machine ... it doesn't work. The best way to describe the error is to say with my Rthreshhold is set to 1, by the time w2k gets to the OnComm event ... the other characters are already in the buffer, where as in w98 it seems only the first character is in the buffer. Are serial ports handled that much faster in 98? Does anyone have any idea's on how to fix this problem?

Comm Ports?
How do you detect how many Comm ports are on a computer?

Comm Ports And VB Can You....HELP!!
Help VB Gurus!,

I am working with a problem that I HOPE can be solved using VB, perhaps using API calls, but the only API code that I use is borrowed, moved to modules and accessed with functions that I understand because the API is way beyond me. Here is a basic outline of the problem:

A PC on a ship needs to communicate with an MCS system that monitors a large number of sensor inputs around the ship. The current method of doing this uses a form with a mscomm control and a Timer control. The Timer control checks the I/O status (ie sends a request for certain sensor inputs, or Waiting for a response). The mscomm_OnCom event is used to trigger data retrieval and processing. Everything currently works fine until a user begins to drag windows around or do other things that occupy the system for more than 2 seconds (the MCS drops communication after a 2 second timeout limit) and then the monitoring system crashes (or ceases to monitor). The problem seems to be that the VB code is not “High” enough in the system priority list. The obvious answer is to have a computer dedicated to the sensors, but because of space limitations this is not a desirable solution. The ultimate goal of the app is to store real time sensor data in a database, and to allow the user to select which sensors to monitor. The MCS system can accept a request for up to 70 sensors in a block and the communications take around 2ms from request for data to data recieved …. Ok, enough back ground. Four solutions seem viable: 1) Use the API to adjust the priority of the VB app at run time. So that no matter what the user does the Monitoring app receives processing time for at least 2ms out of each second. 2) Write the equivalent of a “TSR” that handles the I/O and keeps the MCS connection open and either places the data in the database or holds it in a buffer that the App can access. 3)Use "C" to write an interface. (I have NO experience with C, but understand that it allows a great deal more control over the OS than VB.) 4) Find or Develop an interface card that will allow communication with the MCS to remain open and communicate with the program in a less time critical manner. (Least desirable solution).

Any help and/or suggestions on how to accomplish the goal would be greatly appreciated. I find myself in way over my head. I hate it when everything works except when the client goes to use it, and then he does things that weren't part of the description!

Thanks,

Hunter

ps. There is a similar post in the API forum. In case any one else is interested in this sort of problem I will post replies here if there are any viable solutions posted there and vice versa. Thanks again!

Comm Ports
I am currently creating a VB app to run on a laptop or PC and to allow the user to choose to print a barcode label from an IP address, comm port, or a local printer. The problem is I do know how to programatically figure out how many comm ports the laptop/pc has and to display the appropriate number of the available comm ports in a drop down box to allow the user to select which one the app should use.

Any help would be great on how to do this.

Thanks

Comm Ports
How easy is it to print characters to the comm port?

I am a Qbasic user who currently uses the OpenCom statement.

Mscomm In More Than 16 Comm Ports
I am using VB to communicate with a embedded bluetooth device. The device act as a virtual commport.

The problem is that the device may connect in any available commport from 1 to 255. Using vb's Mscomm we can acces only 1 - 16 commports. The program works without any problem if the virtual comm port is < 16.....

I was able to use readfile api instead of mscomm control and able to acces all commport....... but i was unable to get the path name of the virtual serial port.

some one may help to tackle this problem.

R.V.Raghav

Mscomm (comm Ports)
I am writing an application that uses the MSComm Control. Will my application have access to the drivers/ports on a windows NT 4.0 Server that is not logged in? No, we do not have a server to test it on until we distribute it.

Listing COMM Ports
I know this has been discussed before but the search feature has been disabled. What I am looking for is a way to find the current COMM ports on the system running my program.

Thanks in advance!

How To Detect The No. Of Comm Ports
Hey ,

Can u guys pls tell me is there any method to detect the number of Comm ports in a machine.
IF its stored in registry then whats the path or is there any API for that

Thanks in advance

Detecting Comm Ports
Can anyone tell me how to use VB to detect which
comm ports (COM1, COM2, etc...) are installed on
the computer the app is running on?

Much thanks if you can.

Guinness

Selecting Comm Ports
Hi People,

I have a form with a menu called Communcation>Comm Port>Comm 1 ....through to Comm 8.

When i click on a comm choice i want to select that comm port, but how do i code that?

I know i can do PortOpen, but i want to have it so only 1 comm choice can be 'checked' at one time. and so that only 1 comm port can be used at one time.

Also being quite new to this VB thing i'm not sure if this next question is v hard or easy....but here goes.. what would be ideal is for the software to determine what comm ports are present on the machine and dissable the non-present ones within the menu dropdown. How do i do that??

Any help, or sample code of choosing comm ports would be excellent. Even i nudge in the right direction would be appreciated

Many thanks

John

Big Trouble With Comm Ports
The target machines for my application have comm ports 1,2,5,6. I would still like to use my application on machines with less than that number of comm ports(just with lost functionality)

I'm using this function

Code:
Sub SVO58ports(i As Integer)
'This sets up the ports for the SVO5800 VCR
MsgBox "before case"
Select Case i
Case VCR1_INDEX
MsgBox "case 1"
VCRForm.VCRComm(i).CommPort = SVO58PORT1
Case VCR2_INDEX
MsgBox "case 2"
VCRForm.VCRComm(i).CommPort = SVO58PORT2
End Select
MsgBox "after case"
On Error Resume Next
For j = 0 To 1 Step 1
MsgBox ("j =" & j)
VCRForm.VCRComm(i).InputLen = 0
VCRForm.VCRComm(i).PortOpen = True
If Err And (VCRCommFind(i) = True) Then
MsgBox "VCR " & i + 1 & " is unavaliable"
VCRCommFind(i) = False
Err = 0
Else
If VCRCommFind(i) = True Then

VCRForm.VCRComm(i).InputMode = comInputModeBinary
VCRForm.VCRComm(i).Settings = "38400,O,8,1"
End If
End If
Next

End Sub

When i am in the development environment, this works perfectly fine.

If i make an exe i get as far as message "before case" before i get a run time 91 error.

Connect COMM Port Of One Computer To Mouse Port Of Another
I would like to control the mouse of one computer with commands sent through the COMM port of another computer. This would allow me to automatically run certain data acquisition programs on the second computer withoun my having to point and click. I've been searching for information about this in the forums and on the web, but I haven't found anything. Any help would be appreciated.

Unassociating Hardware (COMM Ports)
I am developing code for a device that uses an FTDI USB<>RS232 chip. Every new device I plug in gets assigned a different COMM port, instead of using the first available. In other words, I have COMM ports 3-9 marked as "in use", with no hardware attached; when I try to re-assign the COMM port number. Apparently Windows is attaching a COMM port for each new board I plug in.

When I plug in a device, its trying to use COMM port 10, instead of 3, even though only COMM PORT 1 is the only port showing in hardware manager. I know Windows (2000) is remembering the association somewhere in an .inf, but where??

Shot In The Dark (Comm Ports)
Hi all
I have a program that uses 6 comm ports through a USB to serial convertion.
Now the 6 comm ports are running at:

3: "4800,n,8,1"
4: "19200,n,8,1"
5: "9600,n,8,1"
6: "1200,n,8,1"
7: "9600,n,8,1"
8: "9600,n,8,1"

now when I run the program it communicates fine with all of the comm ports.
I then close the program, and then try to run the program again, and it fails to communicate with comm port 6. (the comm port using "1200,n,8,1")
if I move the comm ports around it follows the device communicating at "1200,n,8,1".
The only way I can get it to work again is shutting down the computer and restarting.
arrrgh
Has anybody had this problem before and is there a way around this.

Thanks in advance

Device Names On Comm Ports
Hi Guys

Can somebody help me I am new to eVB. I am trying to get the names of devices that are on a comm port to be displayed in a listbox. I have seen this done in other programs like ones that let you select what comm port a Navman is on.

Thanks for any help

Using An Array To Check/assign Comm Ports?
I'm sure this is something real fast and easy but I've been trying different things for a couple of hours and so far have had no luck. I'm really hoping somebody can point me in the right direction on this one.

I downloaded (from here) this .zip file which creates an array based on commports from 1 to (whatever you declare as a constant). Then it checks if that commport is available and if so makes it enabled in a menu (which is generated from the array).

It works great but I'm trying to do a couple of additional things. One, I want to assign the "default" comm port from a database file (which I'm currently doing). When the program is launched, I want the currently selected comm port to be "checked" in the menu list. Also, if the user selects a different comm port from the menu, I would like to make that commport be an integer so that I can then store it in the database (as the new default comm port).

I've been trying several things but each thing has not worked. I've gotten errors from Wrong Type to Variable Not Defined.

Does anyone have any suggestions on what I'm doing wrong. I'm including the "original" code (because the code that I've been working on is just riddled with comments and commented-out errors.

I'm pretty sure this is a quick, no-brainer type of fix but it is just not clicking for me (sad, I know).

Any help would be greatly appreciated.

DTFan

Communicating To Serial Ports With Comm Port Number Greater Than 16

I want to connect to the serial port with comm port number greather than 16, im able to connect to ports with comm port number less than 17 using MSCOMM control in visual basic, but i need to communicate to ports till 256, can anyone please help me out on this.