Functional description
5
gas-lab
Q1
Page 61
5.3.1.3
Message processing; messages and groups
Note:
The message processing function of the monitoring module runs
completely independent of the device’s gas quality measurement monitoring.
Therefore, this functionality of the monitoring module is provided with a separate
error listing and an own logbook.
Please take into consideration that the rules of this message processing differ
considerably from those of the monitoring of the gas quality measurement (see
above); for instance, the acceptance mechanism is totally different. If you know
the DIN 19 235 standard (
Signalling of operating conditions
), you may be
familiar with many terms mentioned in the description below. The message
processing of the Q1 is oriented towards this standard wherever it has proved to
be useful and possible with regard to the monitoring function.
The message processing of the Q1 may manage up to 64 messages defined by
parameterisation. In principle, there are different types of conditions to be
signalled which can be mapped to such a message. The operator himself
defines the events that shall result in messages within the message processing
by parameterising the device.
First, the status of a digital message input (set/not set) can be evaluated as
message. Messages generated by the device itself during operation may also
be integrated in the message processing, such as a gas quality alarm.
Second, measurements can be monitored for limit violation. This applies to
measurements supplied via analogue inputs or measured values generated
internally. In addition to monitoring upper and lower hint limits, it is also possible
to
monitor gradients
. The gradient monitoring observes measurement changes
within defined time ranges: If the difference between the highest and lowest
values of a measured quantity exceeds the defined maximum value within a
parameterised time range, the condition for generating the message
Hint limit
gradient
has been met.
Note:
All single messages referring to measurements are also pending if the
associated input value is regarded as being disturbed.