CC-Link System Master, Local Module User's Manual QJ61BT11

4 FUNCTIONSMELSEC-Q4.2 Basic FunctionsThis section explains the basic functions of the QJ61BT11.4.2.1 Communication with the remote I/O stationsTwo types of communication modes are available for the CC-Link system: remote netmode and remote I/O net mode.(1) Remote net modeIn this mode, it is possible to communicate with all stations (remote I/O station,remote device station, local station, intelligent device station, and standby masterstation). Thus, various systems can be configured according to their applications.(2) Remote I/O net modeIn this mode, a high-speed cyclic transmission is performed for a systemconsisting only of the master station and remote I/O stations. Because of this, thelink scan time can be shortened when compared to the remote net mode.The following provides an overview of the communication between the masterstation and a remote I/O station using the remote I/O net mode. In thecommunication with the remote I/O station, the on/off data of the switches andindicator lamps are communicated through remote input RX and remote outputRY.PLC CPU Master station Remote I/O stationNetworkparameters1)NetworkparametersAutomaticrefreshparametersBuffer memoryX3)Automatic refreshRemote inputRX2)Link scanInputY4)Automatic refreshRemote outputRY5)Link scanOutput[Data link startup]1) When the PLC system is powered on, the network parameters in thePLC CPU are transferred to the master station, and the CC-Link systemautomatically starts up.4 - 3 4 - 3