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Entry type: FAQ Entry ID: 39170, Entry date: 08/20/1996

Distributed I/O on SIMATIC M7

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What is to be noted when implementing distributed periphery on SIMATIC M7 ?

The following is to be noted when implementing distributed periphery (DP):

  • The distributed periphery is connected to the IF964-DP module.
  • Only a DP module can be assigned to an M7-CPU or an M7-FM.
  • The RMOS operating system requires at least 8 Mbytes and RMOS-DOS or RMOS-DOS/Windows at least 16 Mbytes of main memory extension.
  • Parameterization (of the slave stations) is done through hardware configuration (open master system). The NCM option package is not required for parameterizing.
    If the DP slave is not in the hardware catalog, but there is a type file, this can be imported as follows:
    • Copy type file into the Step7_V2\S7data\Typdatei folder.
    • Execute the Options - Update DP Type Files function in the hardware configuration.
  • No ISA accesses may be made on the distributed periphery.
  • If a slave station breaks down, the CPU or FM goes into STOP mode if no task has been announced to the diagnostics server with M7LinkDiagAlarm. You can log in to the diagnostics server by calling M7LinkDiagAlarm. Using RmGetMessage you can check whether a message has arrived from an M7 server (e.g. alarm server). M7GetDiagAlarmAddr provides the logical base address of the slave that sent the alarm.
  • A failed slave station can be identified as follows:
    If "Start when setpoint configuration >< actual configuration" is selected in the hardware configuration, the CPU goes into RUN status even if on or more stations are not available at start-up.
    In order to determine which stations are available ("Life list"), you can proceed as follows:
    • Set "Start-up when setpoint configuration >< actual configuration" in the hardware configuration.
    • Using "M7DPNormDiagnose" read the diagnostics data of each station and evaluate the station status (byte 0...5). You can create your own life list from this diagnostics data.

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