F161_Mrcv Read Serial Data From The Mcu's Com Port - Panasonic FP Series Programming Manual

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Data transfer via communication ports

Use this instruction to copy the data received in the MCU from the external device to the specified

receive buffer in the CPU. The receive buffer is defined by d1_Start and d2_End.

This instruction also exists as a P instruction (for FP2/2SH, FP3/5, FP10/10SH PLC types), which

is only executed at the rising edge of the EN trigger. Select [Insert P instruction] from the

"Instructions" pane if you require a P instruction. To facilitate reuse, the instruction then appears

under "Recently used" in the pop-up menu. Press <Ctrl>+<Shift>+<v> within the programming

area to open the list of recently used elements.

Do not execute F161_MRCV unless the end of reception has been verified by evaluating the

"reception done" flag. Polling the data using F161_MRCV does not work correctly! The "reception

done" flag can be evaluated using the IsReceptionDone (see page 760) function. Or use the

system variable sys_bIsComPort1ReceptionDone, sys_bIsComPort2ReceptionDone, or

sys_bIsToolPortReceptionDone, depending on the port. The end of reception can also be

determined by time-out using the IsReceptionDoneByTimeOut (see page 761) function or by

checking the contents of the receive buffer.

The number of bytes received is stored in the initial address specified by d1_Start of the receive

buffer. If the data received exceeds the ending address specified by b2_End, an operation error is

detected. The data which has been received up to d2_End will be stored. F161_MRCV also clears

the receive buffer (see page 746), resets the "reception done flag" and allows further reception of

F161_MRCV is supported by all PLCs: If suitable functions and system variables are used instead

of flags, PLC-independent programs can be created which handle communication for CPU

communication ports as well as for MCU ports. PLCs not using MCU ports simply do not translate

the F161_MRCV instruction.

d1_start + 1

d1_start + 2

d1_start + 3

d1_start + 4

Read serial data from the MCU's COM port

Storage area for the number

of bytes received

Storage area for the data