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Predefined Item/Point Names 45

READCOMPLETE Item

The READCOMPLETE item is used to access the state of initial reads on all items in

the corresponding topic. If the topic is opened and no item is advised, the value of the

READCOMPLETE item is 0. After all activated items have been read once, the

READCOMPLETE item changes to 1. If at least one item could not be read the

READCOMPLETE item alters to –1 indicating there have been read errors.

If at least one new item is advised now READCOMPLETE changes to 0 and after

this/these item(s) has/have been read it changes to 1 or –1 again.

Poking a 0 to this item resets the internal read states of all items in this topic. This resets

the READCOMPLETE item to 0. If all items are read again after this poke, the

READCOMPLETE item changes back to 1 or –1.

I/O Type: INTEGER

ACCESS: READ/WRITE

RANGE: -1,0,1

POLLNOW Item

Poking a 1 to the predefined POLLNOW item forces all items within this topic to be

read immediately. This is useful if you want to get the newest values from the device,

regardless of its updateinterval. You can use this if you want to trigger the reads within a

topic by your own.

I/O Type: DISCRETE

ACCESS: READ/WRITE

RANGE: 0,1

Note You can use POLLNOW and READCOMPLETE for measuring of the longest

interval. Create a topic with updateinterval 0. Poke POLLNOW to 1 and

READCOMPLETE to 0 and store the actual time. Then wait until

READCOMPLETE changes back to 1. The difference between the current time and

the stored time equals the updateinterval.

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Siemens SIMATIC NET Guida Utente Pagina 49