GWY-01-PBS-014055.3 DATA EXCHANGEThe Master Profibus is usually a PLC (Siemens S7 or others) but it could be a PC baseddevice as well. The Gateway Profibus is always Slave in the Profibus network.PLCRFIDControllerRFIDControllerRFIDControllerRFIDControllerRFIDControllerGWY-01-PBS-01Subnet16™ NetworkProfibus NetworkProfibus MasterProfibus SlaveFigure 19: Profibus-DP Network DiagramBasically two shared memory areas (Exchange Areas) are used to exchange informationbetween the SLAVE and the MASTER, both devices provide information to each other.INPUTAREAOUTPUTAREAPLC GWY-01-PBS-01WriteReadWrite ReadExchange AreasMaster SlaveFigure 20: Profibus Communication – Data Exchange Areas DiagramInput and output areas always refer to the Master: this means that the Gateway writes to theInput buffer and the PLC writes to the Output buffer.The dimension of the exchange areas can be set to different values by the PLC through theGSD file: the Gateway Profibus allows up to 152 bytes as a combined total of the Inputand Output Areas.NOTEFor further information regarding Fieldbus interfacing includingdownloadable support files, go to the HMS website athttp://www.anybus.com, choose the link to the support page, select theAnybus-CompactCom product type and then your network type.
