DART Controls MPD CONTROL Serie Manuel D'instructions page 19

Parameter 14 – Keypad Mode
This parameter selects the operating mode of the front-panel push buttons. In some
applications, increasing or decreasing the scroll rate provides the user more controllability
when entering settings. Parameters 14 and 15 affect only the Up and Down buttons when
the user interface is in Running Mode. These settings also apply to remote Up / Down
buttons which are attached via the -1 option board.
Mode 1: Linear, Constant Rate
In linear mode, pressing and holding the Up or Down buttons will cause the display to
continuously change value in the requested direction until either the Display Minimum
or Display Maximum is reached. The displayed value will scroll at a constant rate which
is specifi ed using parameter 15.
Mode 2: Non-linear, Accelerating Rate
In non-linear mode, pressing and holding the Up or Down buttons will cause the
display to continuously change value in the requested direction until either the Display
Minimum or Display Maximum is reached. The displayed value will initially scroll at a
slow rate and increase in speed until the maximum scroll rate is achieved. The initial
scroll rate is specifi ed using parameter 15.
Parameter 15 – Keypad Scroll Mode
This parameter sets the scroll speed for the front-panel push buttons. The function of this
parameter varies slightly depending on the Keypad Mode. See parameter 14 for more
details.
Parameter 16 – S1 / S2 Input Edge & Prescaler Confi guration
This parameter determines how the MDP processes the S1 and S2 signal inputs. It specifi es
which signal edge is used for measurements and the value of the internal frequency dividers
or prescalers. Modes with prescalers greater than 1 should only be used if the input pulse
rate on S1 or S2 exceeds the unit's maximum native pulse rate (see specifi cations for details);
otherwise, the control loop may become sluggish and unnecessarily inaccurate. Use the
following chart to confi gure this parameter. As an example, assume an application requires
input pulse rates on S1 of 120,000 pulses-per-minute and S2 of 35,000 pulses-per-minute.
According to the electrical specifi cations, the unit can only accept 50,000 pulses-per-minute
on each the S1 and S2 inputs. With this in mind, the S1 and S2 prescalers should be selected
as Falling / 4 and Rising / 1, respectively. In this case, parameter 16 would be set to 2.
Parameter 18 – Power-up Mode
This parameter defi nes the mode which determines the default Running Value when power
is initially applied to the MDP.
Mode 1: Default to Zero
When in this mode, the unit will default to zero (display units).
Mode 2: Default to Power-Up Value
When in this mode, the unit will default to the Power-up Value, parameter 19.
Mode 3: Default to Previously Running Value
When in this mode, the unit will default to the previous running value before power
was removed. A previous running value must have been active for at least 3 seconds
to be recalled after power has been disconnected and reapplied.
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