摘要 |
A method for monitoring an automation unit with a control unit (3) and several terminals (1,2), whereby the terminal can adopt at least two status values. At least some of the previous status changes can be subsequently reconstructed. The control unit (3) receives a message telegram from one of the terminals (1, 2), whereby the one terminal (1, 2) outputs another message telegram only after it has received an acknowledgment signal (Q) from the control unit (3). The message telegram contains at least one first transition component (E01), which indicates a transition from a first state value to a second state value of the at least two state values, and contains at least one second transition component (E10), which indicates a transition from the second state value to the first state value of the at least two state values.
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