16F877 USAR & no standard MSCOMM VB6 speed

[wirecut]

Hi,

on the 16F877 there are a lot of different speed, more very high, but unfortunatelly unsupported by the VB6 MSCOMM.

There are any other way to use the non standard speed instead of the use of the API.

Ciao

Leo

[C_Moore]

Hi wirecut,

Can you give a example of what you are talking about?

[wirecut]

Hi

if we would use 250.000 bps, the USART on the PIC can transmit/receive at this speed, but the VB6 have the maximum speed of 115.200 bps.

Ciao

Leo

[Maverick]

I was using WSC32.DLL (google WSC4VB) it was a while back but i am sure it supported 250,000 baud.
It might be worth considering swapping over to USB

[wirecut]

Hi Maverick,

thanks for the suggestion, but as you can see in the link, the maximum speed supported is 115.200 bps.

http://www.marshallsoft.com/wsc_ref.htm

In the near future will go USB, but now I need to overcome the barrier of 115,200 set by MSCOMM.

Ciao

Leo

[wastrix]

Originally Posted by wirecut

Hi Maverick,

thanks for the suggestion, but as you can see in the link, the maximum speed supported is 115.200 bps.

http://www.marshallsoft.com/wsc_ref.htm

In the near future will go USB, but now I need to overcome the barrier of 115,200 set by MSCOMM.

Ciao

Leo

Where does it say that? All I could see is that that is the maximum set speed, but directly below that it said you can use different baud rates if you want.

[wirecut]

Hi,

on the data sheet of the 16F877 (page 96 DS30292C) there are mentioned the fantastic speed of 1.250 kbaud or the lesser 1000, 625, 312, 250, 230, 156 kbaud.

All of this speed cannot be used by the VB6 due the MSCOMM limitatio to the maximum speed of 115.200

Ciao

Leo

[C_Moore]

From what I see in the MSDN help for VB6 it goes up to 256000

[wirecut]

hi Charlie,

please give to me the link of the related info on MSDN.

Ciao

Leo

[C_Moore]

I would if I could.I have MSDN for VB6 installed.I will try to copy the section and paste it in a forum post.

[C_Moore]

OK here is a section from the help.
Take a look at the baud settings.

     Sets and returns the baud rate, parity, data bit, and stop bit parameters.

Syntax

object.Settings [ = value ]

The Settings property syntax has these parts:

Part Description 
object Anobject expression that evaluates to an object in the Applies To list. 
value Anstring expression representing the communications port settings, as described below. 


Remarks

If value is not valid when the port is opened, the MSComm control generates error 380 (Invalid property value).

Value is composed of four settings and has the following format:

"BBBB,P,D,S"

Where BBBB is the baud rate, P is the parity, D is the number of data bits, and S is the number of stop bits. The default value of value is:

"9600,N,8,1"

The following table lists the valid baud rates.

Setting

110 
300 
600 
1200 
2400 
9600 (Default) 
14400 
19200 
28800 
38400 
56000 
128000 
256000 


The following table describes the valid parity values.

Setting Description 
E Even 
M Mark 
N  (Default) None 
O Odd 
S Space 


The following table lists the valid data bit values.

Setting

4 
5 
6 
7 
8 (Default) 


The following table lists the valid stop bit values.

Setting  
1  (Default) 
1.5  
2  


Data Type

String

[Richard]

but the VB6 have the maximum speed of 115.200 bps.

If you're using a standard PC's serial port you will not get above 115200 baud. I hit the same problem and had to get a PCMCIA serial card which will go to 921600.

[wirecut]

Hi Richard
I have installed one add on PCI card that have four serial port and the maximum speed show on the instruction is 921000.

Hi C_Moore,
I have tried this setup:

MSComm1.Settings = "256000,n,8,1"

and the compilation goes without error, but when I run the program, sending something to the serial port (Com:7) this message appear:

Run time error '8018'
Operation valid only when the port is open,

and pushing debug button, is show the statement in error:

MSComm1.Output = Chr$(1) & Chr$(19) & Chr$(255) & Chr$(0) & Chr$(0)

but consider if I set this set up

MSComm1.Settings = "115200,n,8,1"

all work perfectly.

Ciao

Leo

P.S. Strange that in the help of MSDN the speed of 115200 in not mentioned.

[TEEGEE]

http://www.8051projects.net/e107_fil...2138_vbcom.pdf

exp :
Private Sub MSComm1_OnComm()
MSComm1.Settings = "256000,8,n,1"
End Sub

work whis USB>serial interface

[wirecut]

Hi TEEGEE,

many thanks for you suggestion.

I have read doc at the link, but following the instruction (is show an old version; is for VB5) my problem remain unresolved.
I'm using VB6 with SP6 and I use the following statement:

Private Sub Form_Load()
  On Error Resume Next         
  MSComm1.CommPort = 7 
  ' MSComm1.Settings = "19200,n,8,1"    ' OK
  ' MSComm1.Settings = "115200,n,8,1"   ' OK
  ' MSComm1.Settings = "128000,n,8,1"   ' no message
  ' MSComm1.Settings = "250000,n,8,1"   ' no message
  ' MSComm1.Settings = "256000,n,8,1"   ' no message
  MSComm1.PortOpen = True
  MSComm1.Output = "test message"

I have uncommente every setup and you can see the result for every trial.

Are you using VB6 with SP6.

What do you think about?

Ciao

Leo