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Technical Manual
5-12
Use of inputs and outputs
Internal I/O’s are included on some of the I/O-modules that the G4 instrument
can be equipped with. Different module types have different number of inputs and
outputs. A DIO8 module have 8 inputs and 8 outputs while the weight conversion
modules HS WF2, WF IN and WF IN2 each have 4 inputs and 2 outputs.
All input and output functions are controlled by set-up parameters in the instrument.
Digital inputs
The digital inputs can be used for remote operation of the instrument.
Digital outputs
The digital outputs can be used for control of external equipment and for indication of
instrument status.
Analog outputs
To produce analog outputs from the G4 instrument, a one channel AOUT1 or a four
channel AOUT4 module is used.
The analog output signal will represent a selected signal in the instrument in form of an
analog current or voltage signal.
All analog output functions are defined by parameters in sub menu
‘Analog Outputs’, see chapter ‘Set-up’.
Filter function
In the instrument the weight value is produced in two forms, unfiltered and
filtered. The ‘unfiltered’ weight is actually also filtered but with a faster filter than the
‘filtered’ weight value but for simplicity it is called unfiltered.
The unfiltered weight value represents the transducer load with the smallest delay. This
means that the instrument will respond rapidly to changing load, but
the weight display will be unstable if the load is fluctuating. The filtered weight value will
give a smoother weight display, but the response on changing load
will be delayed. Weight values are produced within the instrument at the selected
‘Update Rate’.
Switching between filtered and unfiltered weight
The instrument automatically switch between unfiltered and filtered weight in order to
make the weight display fast when the load on the scale changes, but stable for
constant load. The parameter ‘Filter window’ controls the switching between filtered
and unfiltered weight.
The scale will switch to filtered weight when the difference between the filtered weight
and unfiltered weight values is smaller than ‘Filter window’.
The scale will switch to unfiltered weight if the difference between the filtered weight
and unfiltered weight values is larger than 4 times ‘Filter window’.
Filter characteristics.
The parameter ‘HSWF Update R.’ / ‘WFIN Update R.’ selects the update rate
and filter characteristics of the weight conversion. The two different types of
weight conversion modules have different ranges of settings.
The filter of the G4 Multi Channel Weighing Instrument will very effectively suppress
any disturbances at frequencies above the –90 dB frequency.