The task pointer to the Cascade Historian program.
An optional buffer containing an error message.
The length in bytes of retbuf. If retbuf is non-NULL, this must be a valid non-zero length. If retbuf is NULL, this parameter is ignored.
The name of a history.
The value and time of the last data item in the history.
ST_OK on success. Otherwise ST_ERROR, and the retbuf will contain a NULL-terminated character string with an error message. If the return value is ST_OK, the retbuf may not contain useful information.
This function returns the value for the last data item in the history. This item may be either in a file or in memory.
This function corresponds to the Cascade Historian latest command and the hist_latest dynamic library function.