General-Purpose Communication - Panasonic FP7 Series User Manual

1.2 Overview of Communication Functions

1.2.4 General-Purpose Communication

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Overview of function
● General-purpose communication is used when PLC executes communication in accordance
with the protocol of the partner device.
● Formulation and sending of command messages to the partner device, and reception
processing of responses from the partner device, are performed by the user program.
Sending/receiving of data with an external device is executed via given operation memory
(e.g. data register).
● Data are sent by converting commands in accordance with the partner device as strings into
ASCII text, setting them into a given data register, and executing GPSEND instruction.
● Response received from the partner device is temporarily saved in the buffer. Based on the
reception done flag, GPRECV instruction is executed. The ASCII strings can be converted
into numerical data, etc. as necessary, by the user program.
● The data size that can be sent or received in a single communication is up to 4,096 bytes.
(including control codes)
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Applications of general-purpose communication
This is used for connection with devices made by differing manufacturers that have dedicated
communication protocols.
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