Panasonic FP2

Communication with External DevicesFP2 Serial Data Unit
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4.1 Overview of Communication with External Devices
4.1 Overview of Communication with External Devices
Communication with external devices is handled through the shared memory provided
in the serial data unit. When data is read from and written to the shared memory in the
serial data unit, it is done using the F151 (WRT) and F150 (READ) instructions in a ladder
program. Sending and reception timing is handled by X and Y contacts allocated to the
serial data unit.
4.1.1 Sending Data to External Devices
Overview of data sending
FP2
CPU unit
FP2 serial data unit
Shared memory
Data
sending
RS232C
device
Data writing using
F151(WRT) instruction
“Sending directive” contact goes on
After the data to be sent has been written to the “Sending Buffer” in the shared memory
using the F151 (WRT) instruction, the “Sending directive” contact is turned on, and the
data is output from the RS232C port.