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VTK-VS-BA-015e-A | User Manual MDS 3200+ Series
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Operation
6.3
Parameters for Dispensing Process
The profile of the system behavior is illustrated below
(Y axis = amplitude of the tappet)
.
This diagram includes the following parameters:
Parameter
Description
Rising
(RI)
This interval describes the time required until the valve is completely
opened. It is adjustable in steps of 0,01 ms
.
Open Time
(OT)
During this phase the valve remains in opened state. It is adjustable in
steps of 0,1 ms.
Max. open time for
≤
80 % NL = 3000 ms.
Max. open time for > 80 % NL = 15 ms.
CAUTION!
When working in External mode, the cycle is initiated with following prop-
erties:
For rising, falling, delay and needle lift, the values determined beforehand
are used. Open time however remains active until the signal returns to the
state “logic 0“
(for needle l
ift ≤
80 %)
.
Maximum open time for needle lift > 80 % is restricted to 15 ms.
Falling
(FA)
The falling ramp of the curve illustrated above represents the time re-
quired for closing the valve. Residual fluid meanwhile is expulsed from the
nozzle compression chamber
(the cavity at the rear end of the nozzle in-
sert)
. The interval is adjustable in steps of 0,01 ms.
Delay (
DL)
This waiting phase between two cycles is adjustable in steps of 0,1 ms.
CAUTION!
For valves operated with connected heating systems, a minimum delay of
2,0 ms is necessary. Lower values can only be achieved, if the heater is
operated via an external control unit.
Needle Lift
(NL)
This parameter describes the stroke of the tappet, compared to its full
value of 100 %. For the range between 80 % and 100 %, the valve works in
bipolar mode. The elevated temperature in this range reduces the average
frequency and the lifetime of the valve. A needle lift between 70 % and
80 % is the best working range.