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Description of the parameters for the inputs:
Name:
Give each input a unique name relating to its function. The name is limited to 40 characters.
A typical counter input could have the name ‘Press shop active energy meter’.
When the input is used to report a condition, an example could be ‘Fault at Oven 3’, or simply
‘Oven 3’ if the operational status is to be communicated.
Counter units:
Here enter the engineering units that the counter value is to have when the pulse value is multi-
plied, e.g. kWh, m³, litres. The length of this unit name or symbol is limited to 10 characters.
Multiplier for counter:
Here enter the multiplier for calculating the engineering units. There is no numerical limit to this
factor!
In the case of an electricity meter with kWh as units, where the transformer ratios cannot be
adjusted, the multiplier is given by the formula
Vv × Vi / pulses_per_kWh
, where Vv is the voltage
transformer ratio and Vi is the current transformer ratio.
If the transformer ratios can be adjusted at the meter, the multiplier is given by
1 / pulses_per_
kWh
.
If a water meter, for example, has m³ as counter units and a pulse value of 1000 pulses per m³, the
multiplier will be 0.001 (m³ per pulse).
Parameters for derived variable calculation:
The derived variable calculation is used when a counter or transducer is connected to the input.
Connecting a counter:
In order to also determine the consumption per hour from counter inputs, the parameters can be
calculated directly from the multiplier for the counter. To have this done, simply click the
Calculate
from the multiplier for counter
button. The four date entry boxes –
Minimum pulse frequency,
Variable at minimum pulse frequency, Maximum pulse frequency, Variable at maximum
pulse frequency
– are then completed automatically.
Figure 14
Calculation of the parame-
ters from the multiplier for the
counter
Connecting a transducer:
The derived variable calculation is also used when a transducer with a frequency output signal is
connected to the input. These devices measure process variables such as temperature, humidity,
etc. and generate a pulse frequency that is proportional to the measured variable. In this case,
the four data entry boxes –
Minimum pulse frequency, Variable at minimum pulse frequency,
Maximum pulse frequency, Variable at maximum pulse frequency
– must be completed
manually using the data specified for the transducer.
