Siemens S7-200 System Manual page 99

Using the Text Display Wizard to Configure the S7-200 CPU for Your Text Display (TD) Device
● TD_ALM_x (where x is the TD configuration number)
Text Display (TD) User Manual
System Manual, 08/2008, A5E00765548-03
– Your user program uses this subroutine to call the alarm by the symbolic name
(configured by the Text Display wizard). This subroutine requires the S7-200 Symbol
Table.
– Your user program should call TD_ALM_x on every scan when the alarm is present.
Figure 4-33 Summary Dialog
Note
The TD_CTRL_X subroutine will clear the alarm enable bits each time it is called. This
behavior could be problematic if the TD configuration contains alarms that require
acknowledgement. The TD_CTRL_x subroutine may disable these alarms before they
can be displayed and acknowledged on the TD device. Your program logic must
ensure that any TD_ALM_x alarm subroutine that requires acknowledgement remains
enabled until the TD device writes the alarm acknowledgement bit in the CPU.
4.8 Finishing the Configuration for the TD Device
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