25: DATA LINK COMMUNICATION« FC4A MICRO SMART USER ’S MANUAL » 25-11Operating Procedure for Data Link SystemTo set up and use a data link system, complete the following steps:1. Connect the MicroSmart CPU modules at the master station and all slave stations as illustrated on page 25-2.2. Create user programs for the master and slave stations. Different programs are used for the master and slave stations.3. Using WindLDR, access Configure > Function Area Settings > Communication and make settings for the master andslave stations. For programming WindLDR, see pages 25-7 and 25-8.4. Download the user programs to the master and slave stations.5. To start data link communication, power up slave stations first, and power up the master station at least 1 second later.Monitor the data registers used for data link at the master and slave stations.Note: To enable data link communication, power up slave stations first. If a slave station is powered up later than or at thesame time with the master station, the master station does not recognize the slave station. To make the master station rec-ognize the slave station in this case, turn on special internal relay M8007 (data link communication initialize flag) at themaster station (see page 25-6), or in WindLDR select Online > Monitor, followed by Online > PLC Status and click the Ini-tialize Data Link button.Data Link Initialization ProgramIf the master station does not recognize the slave station when the master station is powered up, include the following pro-gram into the user program for the master station.Initialize Data LinkInitializes data linkcommunicationM8120 M8007M8120 is the initialize pulse special internal relay.M8007 is the data link communication initialize flag.When the master station CPU module starts to run, M8120 turns on M8007 for one scan toinitialize the data link communication. The master station will recognize the slave station.
