PRIMER 22.1

Flagging Bit Usage

PRIMER makes heavy internal use of "flagging bits". These are literally bits in an internal word used when selecting items for processing and, unfortunately, they are a finite resource which can at times become exhausted. If you try to perform too many functions at the same time you may see the following message:

LIST will give a table of flagging bit usage by model, allowing you to work out what you need to close down in order to free some flagging bits for the wanted operation.

In order to avoid having to provoke this message in order to find out which bits are being used where, this command will list them on demand.

The example listing here shows that:

The Part tree is using one bit. This is always the case and cannot be changed.
The Contact penetration checker is using 3 bits in model #1.
The Model Check panel is using 1 bit in model 1.
The spotwelder in the Connections panel is using 4 bits in all models.
The deletion panel is using 2 bits in all models.

PRIMER 9.3 has a total of 19 dynamically allocatable flagging bits, numbered 5 to 23. As this example demonstrates some operations (eg DELETE) allocate bits in all models, whereas others (eg contact penetration check) are specific to a particular model.

Bit exhaustion can occur even if not all bits in a particular model are in use, since "all model" operations require that bits have the same number in each model.

Therefore when shutting down panels to free flagging bits it is usually most effective to close those which allocate "all model" bits.

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