Device-Independent Fields Treated Specially by the DNPScanner

Field Name Description
st buffer size Depending on the object type and variation, additional data can be passed back. For these objects, the scan task buffer can be used to transfer this data into the database. Some objects return a single byte, some objects return a time stamp, and some objects return both a byte of information and a time stamp. For objects that only return a single additional value, set this size to the expected data size (i.e. one for single byte status, or eight for a time stamp). For objects that return both the status and the time stamp, the status will be saved as the first byte, and the time stamp will be saved in the subsequent eight bytes (i.e. nine bytes should be allocated). In this case, a special CE function should be used to extract the data.
# of elements

The scan task will buffer data in SSMA if this value is greater than one and the range length value is one.

[note] - Only multiple values from a single unsolicited message will be buffered, and then only up to the number of values specified.
- You will need to use the SCANV CE function to extract value(s) from SSMA.
- When a regular poll is issued, the value will be saved into the first record, with all subsequent records zero'ed.

Two special CE functions have been developed as part of the release.

CE Function Description
SCAN_MSTB(SIrec {,fc} {,stb} [,stb ...]) Returns the scanned scalar data element value from the SSMA area corresponding to the scan input record specified by SIrec. fc is an optional output attribute (of rtUINT8 data element type) for saving the communication fail count. If only the stb value(s) are desired, fc must be NULL. stb specifies attribute(s), of the exact data length, for storing data from the scan task buffer. For example, to save a status and a time value, use [.uint8], [.time stamp].
SCANV_MSTB(SIrec {,fc} {,stb} [,stb ...]) Returns the scanned vector of data element value(s) from the SSMA area corresponding to the scan input record specified by SIrec. fc is an optional output attribute (of rtUINT8 data element type) for saving the communication fail count. If only the stb value(s) are desired, fc must be NULL. stb specifies attribute(s), of the exact data length, for storing data from the scan task buffer. For example, to save a status and a time value, use [.uint8], [.time stamp].

 

[note] A maximum of 254 attributes can be specified for the stb.

These CE functions have been included in the RtapMQDBM.dnp and RtapDbCfServer.dnp executables (libceHooks.sl for RTAP 8.2 on UNIX and libceHooks.dll for Windows).