Publication 1766-RM001A-EN-P - October 2008
528 Recipe and Data Logging
Retrieving (Reading)
Records
Data is retrieved from a data logging queue by sending a logical read
command that addresses the Data Log retrieval file. The oldest record is
retrieved first and then, deleted. The record is deleted as soon as it is
queued for transmission. If there is a power failure before the
transmission is complete, the record is lost.
The data is retrieved as an ASCII string with the following format:
<date><UDS><time><UDS><1
st
Data><UDS><2
nd
Data><UDS>…<UDS><Last Data><NUL>
• where:
<date> = mm/dd/yyyy - ASCII characters (date is optional)
<time> = hh:mm:ss - ASCII characters (time is optional)
<UDS> = User Defined Separator (TAB, COMMA, or SPACE)
<X Data> = ASCII decimal representation of the value of the data
<NUL> = record string is null terminated
• If the Real Time Clock module is disabled in the controller, <date> is formatted as 00/00/0000, and
<time> is formatted as 00:00:00.
• The Communications Device determines the number of sets of data that have been recorded but not
retrieved. See the Data Log Status File on page 526.
• The controller performs a the data integrity check for each record. If the data integrity check is
invalid, a failure response is sent to the Communications Device. The data set is deleted as soon as
the failure response is queued for transmission.
Compare Source A
Source B
Low Limit (LIM instruction)
Test (LIM instruction)
High Limit (LIM instruction)
Source (MEQ instruction)
Mask (MEQ instruction)
Compare (MEQ instruction)
Math Source A
Source B
Input (SCP instruction)
Logical Source A
Source B
Move Source
Table 24.2
Instruction Type Operand
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