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| <== Date ==> | <== Thread ==> |
|---|
| Subject: | mbboDirect record and SHFT field |
| From: | Rod Nussbaumer <[email protected]> |
| To: | epics Techtalk <[email protected]> |
| Date: | Wed, 13 Sep 2017 14:22:01 -0700 |
In the record reference manual for 3-14 record reference manual, it says "the SHFT value is set by device support and is not configurable by the user". The information in the accompanying table supports this, indicating in the 'DCT' field of the table 'NO' for the SHFT field of the record type.
In the R3.14.12.3 dbd file for the mbboDirect, there exists the entry "promptgroup(GUI_MBB)", suggesting that a database configuration tool should be allowed to set the SHFT field. When the database is loaded on an IOC, and the SHFT field has been initialized at dbLoadRecords time, the field behaves as one might expect for that circumstance.
Is that the intended behavior, and the docs are out of sync, or the other way around?
If the SHFT field should really only be set by device support, is there a strong convention for that? The method I recall is to infer from a bitmask supplied in the .OUT field, by counting the number of clear least significant bits. Are there other conventions or preferences?
Rod Nussbaumer Group Leader, Controls TRIUMF Vancouver, Canada