Functional description
5
gas-lab
Q1
Page 69
In addition, measurements and count values are always logged if the input value
has been identified as being disturbed.
It is possible to “freeze” process value archives ". If an assigned message
begins, the corresponding archive continues to log data and stops after a certain
number of entries have been reached. The point of time of the last entry will be
marked
with
hint
PVA
<no.>
freeze
begins
(PVA
stands
for
P
rocess
V
alue
A
rchive) in the error listing and logbook of the monitoring module.
The data logging will only be continued if the assigned message ends.
Simultaneously, hint
PVA <no.> frozen
also ends.
The freezing of measurement archives is useful if you are interested in how a
measurement develops in case a certain event occurs. It may be possible, for
instance, to link the freezing with a centralized message. Then, the freezing will
be activated upon the first beginning of any message of the group. Normal data
logging will not be continued after the end of the last message until the group
has been accepted explicitly, for the centralized message only ends in this case.