User manual

Digital Monitor AMC-1DBx Series User Manual
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6.5 Analog Outputs
The system contains 4 integral analog outputs and can control additional remote analog
outputs on each of the 4 MODBUS channels. An analog output can be configured for
voltage or current, this configuration is controlled by hardware switches located on the
monitor board. There are four switches; one for each integral analog output channel. In
voltage or current mode the database configuration can also provide an additional range
setting; 0-20mA(0-10V) or 4-20mA(2-10V) this is known as range in the database
configuration context.
The analog output is assigned to a Zone. An analog output can be configured for peak or
average operation and this is known as type in the database configuration context. The
peak operation provides the highest gas concentration for the sensors assigned in that
zone while the average provides a sum gas concentration over the number of sensors.
The gas type definition (at the sensor definition) plays a significant role in the peak and
average mechanism. For each gas type definition, there exists system fixed scaling
value which is used to pre-scaled gas readings prior to peak detection and sensor gas
concentration averaging. Gas types like CO and NO2 have different pre-scale values
and are fixed in the monitor’s system. Please refer to the table GAS TYPES FULL
SCALE AND ALARM VALUES for specific fixed pre-scale values.
A gas type like NO2 which has a highest alarm point set to 3ppm will be pre-scale
by 3.3. This will normalizes the gas concentration to the same level as CO which
has its highest alarm point set to 100ppm and uses a pre-scale of 1.0.
This pre-scaling is applied to the analog output level. An additional scaling can be
configured and applied to the analog output above and beyond the gas type fixed pre-
scale mechanism previously discussed and this scaling is known as scale in the
database configuration context. It is applied to final peak or average result.
Additionally there is a filtering of the analog output over a short period of time; 1-
60seconds. This configuration is known as period in the database configuration context.
Remote analog output can take many seconds for their updates and therefore can result
in delayed and reduced filtering. Integral analog outputs offer better filtering in this
respect.
6.6 Logging
The AMC-1DBx can log monitor’s runtime information to various devices and ports. The
monitor has several different information categories:
Sensor,
Relay,
Alarm,
System,
Administration,
Security,
Communication.
The monitor’s information can be logged to the following devices and ports: