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Sensoray 2600 Programming Guide 67 Comport Transaction Functions

condition is detected on the comport’s receive line. The break character may be set to a “printable” character, such

as a carriage return character, to provide a “visual” indication that a break was detected.

Break conditions are sometimes employed as message delimiters. For example, a hand-held barcode scanner may

assert a break when its trigger is squeezed, and again when the trigger is released. The resulting break characters

will then serve as delimiters for the barcode data.

The target comport may be either open or closed when this function is called.

Example: // Configure COM1 on MM number 0 to use a carriage return as its break character.

u32 errstat = S26_ComSetBreakChar( 0, LOGDEV_COM1, 13, 1000, 1 );

if ( errstat & GWERRMASK )

printf( "COM1 error detected.\n" );

else

printf( "Successfully set COM1 break char.\n" );

8.2.3 S26_ComOpen()

Function: Enable transmit and receive operations on a comport.

Prototype: u32 S26_ComOpen( HMM hbd, u8 LogDev, u32 msec, u32 retries );

Returns: Error/status value, as described in section 8.1.1.

Notes: By default, all comports are closed after a MM reset. S26_ComOpen() must be called to enable each comport that

will be used. A comport must be enabled before attempting to send data to or receive data from the its remote serial

device. Before calling S26_ComOpen(), the application should call S26_ComSetMode() to configure the comport.

The target comport must be closed when this function is called. If the comport is already open when this command

is issued, the command will be rejected and the status byte’s COM_REJECTED flag will be set.

The COM_ISOPEN flag will be asserted in the returned status byte if this function executes successfully.

Example: // Open COM1 on MM number 0.

u32 errstat = S26_ComOpen( 0, 1, 1000, 1 );

if ( errstat & GWERRMASK )

printf( "COM1 communication problem detected.\n" );

else if ( errstat & COM_REJECTED )

printf( "COM1 already open.\n" );

else

printf( "COM1 is %s.\n", ( status & COM_ISOPEN ) ? "open" : "closed" );

8.2.4 S26_ComClose()

Function: Disable transmit and receive operations on a comport.

Parameter Type Description

hbd u32

MM handle.

LogDev u8

Logical device identifier for the target comport. Specify a value from 1 to 4 to

address comport 1 to 4, respectively.

msec u32

Maximum time, in milliseconds, to wait for the MM to respond.

retries u32

Maximum number of transaction retry attempts.

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