Rockwell Automation 57C610 Enhanced Basic Language, AutoMax - Manual (Page 65)

6Ć25
Differences Between Allocating Ports A and B
How you use the OPEN statement depends on whether it is being
used with port A or port B. For port A, the OPEN statement is only
used to change the default setup and baud rate for the port. For port
B, the OPEN statement is used to change the default setup and
baud rate and to allocate the port. Port B must be allocated using
the OPEN statement prior to using any of the serial port statements
to communicate through the port.
OPEN Statement Format Used To Modify Port Setup
Characteristics
OPEN device_name" AS FILE #logical_device_number,
SETUP=specs, baud_rate
OPEN Statement Format Used To Set Port Allocation Status
OPEN device_name" AS FILE #logical_device_number,
ACCESS=status
where:
device_name =
The preĆassigned name of the port; PORTA for port A or PORTB
for port B.
logical_device_number =
The number assigned to the port in the OPEN statement. The #
symbol is required. Range: 1Ć255.
The number used when referencing port A or port B in the
CLOSE statement. See Configuring and Using Port A and
Configuring and Using Port B, below.
The number used when referencing port B in the INPUT, PRINT,
GET, and PUT statements. See Configuring and Using Port B,
below.
specs =
A hexadecimal single word constant or integer expression bit
pattern that defines various characteristics for the port. The bit
positions are defined below. The parameters SETUP and
ACCESS cannot be specified in the same OPEN statement.
The default setting is 0D00 (hex). Bits 0Ć7 of the word specify the
terminating character for the INPUT statement as a hex value for
the ASCII character. The specified terminating character must be
an ASCII value between 20 hex and 7E hex. Using an ASCII
value outside this range causes the error message Invalid
string character received" to be logged when the INPUT
statement reads data from the serial port. If these bits are left at
zero (0), the default input termination character, a carriage return
( 0D hex), is used.
When software handshaking (XĆON, XĆOFF) is enabled, XĆOFF
(CTRLĆS, 13 hex) will be sent when more than nine characters
are in the receive buffer. When a task (INPUT or GET statement )
empties the receive buffer, XĆON (CTRLĆQ, 11 hex) will be sent.
The ASCII characters XĆOFF or XĆON can not be transmitted as
user data because they would be interpreted as flow control
commands, not user data.