Siemens SIMATIC PCS 7 Programming And Operating Manual page 88

Appendix
7.1 Allocation request and allocation status
Allocation request and allocation status
● The allocation requirements are defined in the master data library under "Shared
Declarations > Enumerations > ES_AcquireTypes".
The following table describes the available allocation requests sorted by their priorities.
The lowest priority is at the top.
● The allocation states (plural) are defined in the master data library under "Shared
Declarations > Enumerations > ES_AcquireStates".
The following table describes the available allocation states.
88
Allocation request
(Type according to
ES_AcquireTypes)
No request (NoRequest) 0
Preliminary (wait)
(PrelimWait)
Preliminary (now)
(PrelimNow)
Wait
(Wait)
Immediate
(Now)
Takeover
(TakeOver)
Force (safe)
(ForceSafe)
Force (now)
(ForceNow)
Allocation status
Idle
Owner
Priority Network Description
share
- Default value of the allocation variable
Is also used to withdraw an allocation request.
1 Implicit Similar to "Wait", only with implicit release in a
subsequent, higher-level allocation request.
2 Implicit Allocation must be immediately successful or it
fails. Implicit release for a subsequent, higher-
level allocation request.
3 Explicit If no immediate allocation is possible, there is a
wait for the release.
If the passed wait time is zero, the wait may last
indefinitely.
This allocation request fails when a wait time
greater than zero has been configured and this
time has expired.
Explicit release required.
4 Explicit Allocation must be immediately successful or it
fails.
Explicit release required.
5 Implicit With the same allocation identifier (for example,
unit name), an immediate change of ownership
takes place. With regard to errors and wait time;
otherwise like the "Wait" type.
6 Explicit Once the equipment module (EM) to be alloca‐
ted is at an end position (IDLE, ABORTED, etc.
– ORing possible as well) that can be deter‐
mined by parameter, it changes ownership.
7 Explicit Immediate, unconditional change of ownership
by the requesting object.
Comment
Free
Equipment module (EM) is available.
Owner
Allocation has succeeded.
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