9.4.4 Operations of the "Reception Done Copy" Flag and Multiplex Reception
■
Operation and function of the "reception done copy" flag (X4, X5, X6, X7)
● The "reception done copy" flag (X4, X5, X6, X7) turns ON when the GPRECV instruction is
executed and data are copied from the reception buffer to the specified operation memory,
and turns OFF when the END instruction is executed.
■
Processing in the case of multiplex reception
● If the time from the reception of data in the reception buffer to the subsequent data reception
is shorter than the PLC scan time, and the receiving frequency is high, it is possible that the
reception done flag (X0, X1, X2, X3) remains ON and cannot detect sequential receptions.
● In cases where it is necessary to process sequentially received data, constantly execute the
GPRECV instruction, in combination with the "reception done copy" flag (X4, X5, X6, X7).
● Referring to the "reception done copy" flag (X4, X5, X6, X7), you can confirm whether there
are lately received data.
9.4.5 GPRECV (General-Purpose Communication Receive Instruction)
■
Ladder diagram
(Note 1) The above figure shows the case that S1=U0 (CPU unit with built-in SCU) and S2=U1 (port number 1)
are specified by the UNITSEL instruction.
9.4 Receiving Operation
WUME-FP7COM-07 9-21
To Next Page
Loading...
Need help?
General
