Communication with External Devices
FP2 Serial Data Unit
4 − 9
4.2 Programming When Data is Sent
4. The sending completed flag goes on.
When the sending from the RS232C port has been completed, X0 (Sending Completed
flag) goes on.
FP2 serial data unit
Shared memory
Sent buffer
RS232C device
Data register
DT0
Sending directive (Y10: on)
Sending completed flag (X0: on)
FP2
CPU unit
5. The sent buffer is cleared.
At the timing at which X0 (Sending completed flag) goes on, the Y10 (Sending directive)
which went on earlier goes off, and the contents of the sent buffer in the shared memory
are cleared.
FP2 serial data unit
Shared memory
RS232C device
Data register
DT0
Sent buffer
Sending directive (Y10: off)
Sending completed flag (X0: on)
FP2
CPU unit
6. The sending completed flag goes off.
When clearing of the sent buffer in the shared memory has been completed, X0 (Sending
completed flag) goes off.
FP2 serial data unit
Shared memory
RS232C device
Data register
DT0
Sent buffer
Sending directive (Y10: off)
Sending completed flag (X0: off)
FP2
CPU unit
Notes
• This explanation is based on COM.1 of the serial data unit
installed in slot 0.
• The contact numbers are allocated automatically, based on the
slot in which the serial data unit has been installed.
To Next Page
Loading...
