User Manual

CM2U8567E / 04.1999 VISONIK DCS Functions and System Messages VVS18 Siemens Building Technologies
2-76 Function DPO Landis & Staefa Division
2.11.2 GEN, Generate Value Log
Operation GEN is used to generate a DP Value Log. A Value Log can only be generated
if the related point exists in the process image. A DP Value Log is dimensioned
automatically by VISONIK DCS based on the responses as requested in the dialogue
procedure.
VISONIK DCS automatically starts to record data immediately after a Value Log has
been generated.
No
special start or stop instructions are necessary for the processing
of data.
The drawing below shows the structure of a DP Value Log. A Value Log's size depends
on:
•
Recording type,
•
Beginning and end of logging period,
•
Logging interval,
Values with different 'Record Specifiers' cannot be mixed in the same DP Value Log, i.e.
separate Value Logs are required.
If simultaneous recording of instantaneous and mean values from the same ME point is
required then two separated DP Value Logs must be generated, which means Operation
DPO,GEN must be called up twice.
8567Z03E
Address
Parameter name
Interval 1 Min, 5 Min ...
Memory length
is defined by
begin and
end times
DP Value Log
Log Specifier
R.type INST, MEAN, MMM
Starting and stopping
data logging
Value Log structure
Example