53
Closing a Communications Port
Section 4-5
Note
1.
If 256 bytes or more of data is stored in the receive buffer, or the receive
buffer if empty, and the data is retrieved using A$ = INPUT$(LOC(2), #2),
an ILLEGAL FUNCTION CALL ERROR will be generated. Therefore, use
the following program to retrieve the data.
I% = 0
A% = LOC(2)
WHILE (A% <> 0)
IF (A%>255) THEN A% = 255
A$(I%) = INPUT$ (A%, #2)
I% = I%+1
A% = LOC(2)
WEND
4-5
Closing a Communications Port
Communications ports are closed using the CLOSE command.
When a transmission device has been specified using the OPEN command
and the CLOSE command is executed, the data remaining in the transmit
buffer is sent before the port is closed.
When a reception device has been specified using the OPEN command and
the CLOSE command is executed, the data remaining in the receive buffer is
cleared.
All communications ports are also closed by the END, CLEAR, and NEW
commands. They are not closed by the STOP command.
4-5-1
Transmission Control Signals
4-5-2
Transmission Control Signal Timing Charts
After turning ON the power or restarting the Unit, and until each port is
opened using the OPEN# command, the device symbol (peripheral device
name) for each port is as follows:
Transmission Control
Signal Status
The statuses of the transmission control signals (RTS, DTR, DSR, and CTS)
at each point of time are changed as shown in the following table according to
the device symbol (peripheral device name) and transmission control signal
operation specified in the OPEN# command.
Model
C200H-ASC11
C200H-ASC21
C200H-ASC31
Port
Port #1
Port #2
Port #1
Port #2
Port #1
Port #2
Port #3
RTS
OFF
---
OFF
DTR
ON
No
change
ON
---
No change
ON
Model
Port
Device symbol
(peripheral device name)
C200H-ASC11
C200H-ASC21
Port #1
TERM
Port #2
LPRT
C200H-ASC31
Port #1
LPRT
Port #2
LPRT
Port #3
TERM
Содержание C200H-ASC11
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