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| <== Date ==> | <== Thread ==> |
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| Subject: | Compression record returns double value for field "N" over channel access |
| From: | Georg Weiss via Core-talk <core-talk at aps.anl.gov> |
| To: | "core-talk at aps.anl.gov" <core-talk at aps.anl.gov> |
| Date: | Fri, 25 Nov 2022 09:30:09 +0000 |
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The field N (and NSAM) of a compression record should according to specification (https://epics.anl.gov/base/R7-0/6-docs/compressRecord.html) use
ULONG. However, reading the field N over channel access apparently may return a double value: >cainfo RFQ-010:RFS-EPR-110:Cur-ROI-Avg.N RFQ-010:RFS-EPR-110:Cur-ROI-Avg.N State: connected Host: idmz-ro-epics-gw-tn.esss.lu.se:5064 Access: read, no write Native data type: DBF_DOUBLE Request type: DBR_DOUBLE Element count: 1 The assumption is that since input data is an array of doubles, the field N uses same type.
While the above suggests query was handled by a ca gateway, I get the same result when not using a gateway. Seems pvaccess returns a unsigned long type for field N. Is this behavior expected? BR, Georg Weiss European Spallation Source |