摘要 |
<p>A Modbus slave device is operable in an agile mode that allows the slave device to automatically interpret and respond to first-type and second-type message frames conveyed to the slave device by a master device. The slave device detects a first incoming character of a master query message frame generated by the master device. If the first incoming character is a prompt character for the first-type message frame, the slave device interprets the master query message frame as the first-type message frame. If the first incoming character is not the prompt character for the first-type message frame, the slave device interprets the master query message frame as the second-type message frame. If the slave device is addressed in the master query message frame, the slave device performs the command associated therewith and, if required by the command, generates a responsive slave message frame of the same type as the master query message frame.</p> |