Profibus System Integration PDF 4.03MB - Schneider Electric

The following diagram is an example of a complementary block used to read slavediagnostics with MNET5204.Writecommand1Slaveidentification2Exchanges tablePLC Master345ExchangestatusStandard &extendeddiagnostics1) Write commandThis command starts the diagnostics read.2) Slave identificationThis data identifies the SlaveAddress and TypeRequest on Profibus; diagnostics arestored in the master or in the slave.3) MailboxThe DP master uses a protocol called “Mailbox Messaging” to exchange parameterdata between the processor, the master and the slaves. The processor writes acommand into the Mailbox Out and the master executes the command. The responseis stored in Mailbox In.4) Exchange statusThis data provides the operation status and associated error codes.5) Standard & extended diagnosticsThis is an array of 6 bytes for the standard diagnostic and an array of 119 words forthe extended diagnostic.Adjustment DFBPerformed functionThis DFB is designed to modify the 4 thresholds associated with a measure.ReminderThe values displayed come directly from the device and the values modified are writteninto the device.50