1.2 Overview of Communication Functions1-71.2.4 General-Purpose Communication Overview of function General-purpose communication is used when PLC executes communication in accordancewith the protocol of the partner device. Formulation and sending of command messages to the partner device, and receptionprocessing 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 intoASCII 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 thereception done flag, GPRECV instruction is executed. The ASCII strings can be convertedinto 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) Applications of general-purpose communicationThis is used for connection with devices made by differing manufacturers that have dedicatedcommunication protocols.Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
