Operation
Operating modes
35
© Lutz-Jesco GmbH 2015
Subject to technical changes.
150302
BA-10102-02-V02
Stepper motor-driven diaphragm dosing pump MEMDOS SMART LD
Operating Instructions
11.2.2 External operation
The stroke frequency and consequently the delivery capacity of the
dosing pump MEMDOS SMART LD in the
External
operating mode is
determined by the quantity and interval of the incoming pulses in
connection with the set transmission factor.
11.2.2.1 Selecting the operating mode
è
Press
Ext
to start the device.
4
The dosing pump displays the start screen of the
External
operating mode with the symbol .
Int
Start
- +
100%
Fig. 38: Start display external operation
11.2.2.2 Setting the transmission and reduction
The transmission and reduction factors can be set in 1% intervals of 1%
to 1000%. A set value of 100% means that the dosing pump executes
one dosing stroke per incoming pulse signal. For values above 100%, the
dosing pump executes more dosing strokes per pulse signal accordingly.
For values below 100%, the dosing pump executes less than one dosing
stroke per pulse signal, meaning that several pulse signals are required
before a dosing stroke is executed.
The number of pulse signals required for a dosing stroke is displayed on
the dosing pump display for values below 100%.
Int
Start
- +
50% (2)
Fig. 39: Number of pulse signals required (here: 2)
Examples for transmission / reduction
Number of pulses
Setting
Dosing strokes
4
25%
1
2
50%
1
1
100%
1
2
100%
2
4
125%
5
1
1000%
10
Table 30: Examples for transmission / reduction of pulse
signals
In cases of sequences of sequential pulses, it must be noted that the
number of dosing strokes corresponding to the pulses does not always
follow the pulses immediately in certain settings. This is due to the fact
that only entire dosing strokes are executed, e.g. not half or quarter
dosing strokes. Depending on the transmission or reduction factor and
the number of pulses, however, there is a possibility of uneven results
with "pending" pulse signals. In theses cases, the required number of
dosing strokes is only achieved after a number of pulse cycles.
Examples:
The dosing pump receives pulses with a reduction factor of 30%. For the
first stroke, it requires 4 pulses in this setting (4 x 30% = 120%), as 3
pulses (3 x 30% = 90%) are insufficient for one dosing stroke (= 100%).
However, the second dosing stroke is executed after just 3 more pulses,
as the stroke buffer of the dosing pump still has 20% pending from the
first 4 pulses (120% - 100% = 20%) and this is added to the 3 pulses
(90% + 20% = 110%). The third dosing stroke also only requires 3
additional pulses (90% + 10% = 100%). A further 4 pulses are then
required for the fourth dosing stroke.
If pulses are transferred to the dosing pump with a transmission factor of
125%, a dosing stroke is executed for each of the first 3 pulses. With the
4
th
pulse, it executes 2 dosing strokes (3x 25% pending from the first 3
125% = 200%).
The dosing pump has a dynamic stroke buffer which includes the interval
between the pulses in the calculation and adjusts the distribution of the
dosing strokes accordingly.
11.2.2.3 Calculating the transmission factor
The dosing pump MEMDOS SMART LD has a defined stroke volume per
dosing stroke. If a certain dosing quantity is required per pulse, the
corresponding transmission factor can be calculated for the external
operating mode.
i
You can find a simple means of performing the necessary
calculations on the Lutz-Jesco GmbH homepage. To do so,
click on the following link or enter it in your browser:
http://www.lutz-jesco.com/online-helfer-memdos-smart-ld
11.2.2.4 Starting the dosing pump
Precondition for action:
ü
The dosing pump has been connected in accordance with the
chapter 9.2.2 „Connection socket 2“ on page 29.
1.
Press
Start
.
2.
Supply pulses to the pulse input of the dosing pump.
ü
Dosing pump has started.
11.2.2.5 Stopping the dosing pump
è
Stop the incoming pulses or press Stop.
ü
Dosing pump has stopped.
Summary of Contents for MEMDOS SMART LD
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