Implement Serial Communication Using Activex

 

 

For implementationYou can use APIs to implement Windows serial communication, but it is inconvenient. You can also use the Active control.

 

InsertThe Active control Microsoft comm contronl (MSComm ).

 

SComm control attributes

 

MSComm control attributes

 

Commp ORT: Set the serial port number. Type: short: 1-comm1 2-comm2.

 

Settings: sets the serial communication parameters, type CString: B-baud rate P-parity (N-no verification,

E-even verification, O-odd verification) D-byte valid bits S-Stop bits.

 

PortOpen: set or return the serial port status. Type: BOOL: True-enable FALSE-Disable.

 

InputMode: sets the format for reading data from the receiving buffer, type long: 0-Text 1-Bin.

 

Input: Read the data type VARIANT from the receiving buffer.

 

InBufferCount: number of bytes in the receiving buffer; Type: short.

 

InBufferSize: the size of the receiving buffer. Type: short.

 

Output: write data to the sending buffer. Type: VARIANT.

 

OutBufferCount: number of bytes in the sending buffer; Type: short.

 

OutBufferSize: size of the sending buffer; Type: short.

 

InputLen: Specifies or returns the number of bytes read from Input. Type: short.

 

CommEvent: Serial Port event, type: short.

 

Program example

 

Serial Port Initialization

 

If (! M_comm.GetPortOpen ())

 

M_comm.SetPortOpen (TURE );/* Open the serial port

 

M_comm.SetSettings ("4800, n, 8, 1 ");/* Set serial port Parameters

 

M_comm.SetInputMode (0 );/* Set the TEXT buffer input mode

 

M_comm.SetRthresHold (1 );/* The OnComm () event is triggered every time one character is received.

 

Receive data

 

M_comm.SetInputLen (1 );/* Read one character each time

 

VARINAT V1 = m_comm.GetInput ();/* Read characters

 

M_V1 = V1.bstrval;

 

Sending character

 

M_comm.SetOutput (COlevariant ("Hello");/* Send "Hello"