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Thread: watchdog/live bit mechanism

  1. #1
    christopherpara Gast

    Frage watchdog/live bit mechanism

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  2. #2
    christopherpara Gast
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    Default Re: watchdog/live bit mechanism

    There are many ways to create watchdog mechanism. But all of them based on the same idea. Create Variable and change it cyclically, check the changes. I will introduce some of ideas how to manage it.

    1.Create a bool variable that will be change by zenOn from 1 to 0 (REMA + Function: Send value to hardware) and by PLC (with for e.g. 3 second delay) from 0 to 1. On zenOn side create Minimum Limit: 0 with for e.g. 5 second Delay time. Then, if PLC will not change value to 1 in 4 seconds that means we lost connection or PLC stops. On PLC side you can create alarm: when Variable is 1 longer than for e.g. 5 seconds that means zenOn did not change the value to 1 = he stops.

    2. On zenOn side create Variable that will be change cyclically: impulses long for 2 second every 4 seconds (Time control) and on PLC side create function

    ondelay (zenOn_var, 3 seconds delay) OR ondelay (negation (zenOn_var), 3 seconds delay),

    then if for 3 seconds value will not change (from 1 to 0 OR 0 to 1) then in PLC function will indicate to 1 = zenOn runtime stops. Similar but reversed situation to inform zenOn about PLC hang. On PLC create timer function (2 seconds impulses every 4 seconds) and on zenOn side create two Limits for 0 and 1 value with 3 seconds Delay time.

    3. Of course zenOn by himself can control network traffic: System variables > Net… You can also use a I-Bit.

    info: This bit is set, if there is a problem in the communication with the driver or with a single variable. The evaluation of single variables is only supported by spontaneous drivers. Most of the control system drivers however are polling drivers, thus only a general problem in the communication can be indicated (and not a separate one for each variable).

    info: With the standard settings the network service (zenNetSrv.exe) of each client sends a watchdog to the network service (zenNetSrv.exe) of the server all 10 seconds during online operation. If the server responds to at least one of the three watchdogs within the 30 seconds, the client assumes, that the network connection is working.
    Last edited by bernhards : 17th July 2008 at 13:29

  3. #3
    lunzer Gast
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    Default Re: watchdog/live bit mechanism

    Habe folgende Lösung zum Thema Watchdog zwischen SPS und Zenon.

    Sollte dies jemand einsetzen dann bitte ich um einen Erfahrungsbericht, Danke!

    (Die SMS-Funktionen sind natürlich optional)

    In der SPS-TAG anlegen:

    Folgendes Programm in der SPS:
    SPS1_ANA jede Sekunde um 1 erhöhen.
    Wenn SPS1_ANA kleiner 6 dann Kommunikation OK = SPS1_KOMM_ST =0
    Wenn SPS1_ANA größer 6 dann Kommunikationsfehler = SPS1_KOMM_ST=1

    Tags anlgegen
    SPS1_ANA = DINT, SPS-Merker

    SPS1_PROG_HELP = Bool, interne Variable
    GRW1 = 0; 60 Sekunden verzögert , Funktion: SPS1_PROG_EINS(siehe unten),
    GRW2 = 1; 60 Sekunden verzögert, Funktion: SPS1_PROG_EINS(siehe unten)

    SPS1_PROG = Bool, interne Variable
    GRW1 = 0 ;
    GRW2 = 1; Funktion:Send_SMS_SPS1_PROG

    SPS1_ST = Bool, interne Variable
    GRW1 = 0 ;
    GRW2 = 1; 60 Sekunden verzögert, Funktion: SMS_SPS1_ST

    Fuktionen anlegen:
    SPS1_ANA_NULL = SPS1_ANA auf Null setzen

    SPS1_PROG_HELP_NULL = SPS1_PROG_HELP auf Null setzen
    SPS1_PROG_HELP_EINS = SPS1_PROG_HELP auf Eins setzen

    SPS1_PROG_NULL = SPS1_PROG auf Null setzen
    SPS1_PROG_EINS = SPS1_PROG auf Eins setzen

    SPS1_ST_NULL = SPS1_ST auf Null setzen
    SPS1_ST_EINS = SPS1_ST auf Eins setzen

    Skripts anlegen


    Funktionen anlegen:
    SPS1_REMA_GL2 = Skript ausführen SPS1_REMA_GL2
    SPS1_REMA_GR4 = Skript ausführen SPS1_REMA_GR4

    REMA "SPS1_KOMM" anlegen:

    Zustand 1: Wert beliebig, IBIT =1 Funktion: SPS1_ST_EINS

    Zustand 2: Wert = 0, Funktion: SPS1_PROG_HELP_EINS

    Zustand 3: Wert = 2, Funktion: SPS1_REMA_GL2

    Zustand 4: Wert > 4, Funktion: SPS1_REMA_GR4

    REMA SPS1_KOMM in der Variable SPS_ANA aktivieren.

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