Herror ::set_serial_param (
    const HTuple &SerialHandle,
    const HTuple &BaudRate,
    const HTuple &DataBits,
    const HTuple &FlowControl,
    const HTuple &Parity,
    const HTuple &StopBits,
    const HTuple &TotalTimeOut,
    const HTuple &InterCharTimeOut
)

Set the parameters of a serial device.

::set_serial_param can be used to set the parameters of a serial device. The parameter BaudRate determines the input and output speed of the device. It should be noted that not all devices support all possible speeds. The number of sent and received data bits is set with DataBits. The parameter FlowControl determines if and what kind of data flow control should be used. In the latter case, a choice between software control ('xon_xoff') and hardware control ('cts_rts', 'dtr_dsr') can be made. If and what kind of parity check of the transmitted data should be performed can be determined by Parity. The number of stop bits sent is set with StopBits. Finally, two timeout for reading from the serial device can be set. The parameter TotalTimeOut determines the maximum time, which may pass in ::read_serial until the first character arrives, independent of the actual number of characters requested. The parameter InterCharTimeOut determines the time which may pass between the reading of individual characters, if multiple characters are requested with ::read_serial. If one of the timeouts is set to -1, a read waits an arbitrary amount of time for the arrival of characters. Thus, on Windows NT systems, a total timeout of TotalTimeOut + n InterCharTimeOut results if n characters are to be read. On Unix systems, only one of the two timeouts can be set. Thus, if both timeouts are passed larger than -1, only the total timeout is used. The unit of both timeouts is milliseconds. For each parameter, the current values can be left in effect by passing 'unchanged'.

Parameters

SerialHandle (input_control)
 serial_id -> HTuple.long
Serial interface handle.

BaudRate (input_control)
 integer -> HTuple.long / char *
Speed of the serial interface.
Default value: 'unchanged'
List of values: 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 76800, 115200, 153600, 230400, 307200, 460800, 'unchanged'

DataBits (input_control)
 integer -> HTuple.long / char *
Number of data bits of the serial interface.
Default value: 'unchanged'
List of values: 5, 6, 7, 8, 'unchanged'

FlowControl (input_control)
 string -> HTuple.char *
Type of flow control of the serial interface.
Default value: 'unchanged'
List of values: 'none', 'xon_xoff', 'cts_rts', 'dtr_dsr', 'unchanged'

Parity (input_control)
 string -> HTuple.char *
Parity of the serial interface.
Default value: 'unchanged'
List of values: 'none', 'odd', 'even', 'unchanged'

StopBits (input_control)
 integer -> HTuple.long / char *
Number of stop bits of the serial interface.
Default value: 'unchanged'
List of values: 1, 2, 'unchanged'

TotalTimeOut (input_control)
 integer -> HTuple.long / char *
Total timeout of the serial interface in ms.
Default value: 'unchanged'
Suggested values: -1, 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 'unchanged'

InterCharTimeOut (input_control)
 integer -> HTuple.long / char *
Inter-character timeout of the serial interface in ms.
Default value: 'unchanged'
Suggested values: -1, 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 'unchanged'

Result

If the parameters are correct and the parameters of the device could be set, the operator ::set_serial_param returns the value H_MSG_TRUE. Otherwise an exception is raised.

Possible Predecessors

::open_serial, ::get_serial_param

Possible Successors

::read_serial, ::write_serial

See also

::get_serial_param

Module

System

Copyright © 1996-2002 MVTec Software GmbH