feed are ON during quick feed process, and gradual feed exists.
The schematic diagram of slow feed 2 shows the slow feed output when only the quick feed is ON
during quick feed process, and without gradual feed.
The control procedure in the above diagram is consist of 4 processes including quick feed, slow feed,
gradual feed and discharge.
(1) Quick feed-- When the control procedure starts, the quick feed output gives out a signal, and the
corresponding O1 relay is closed. When the weight is added to the quick feed stop value A-b, the
quick feed output signal is cancelled, the corresponding O1 relay is switched off.
(2) Slow feed-- After a period of delay time t1 (quick feed over delay), the slow feed output gives out a
signal, and the corresponding O2 relay is closed. When weight is added to the slow feed stop value AC, the slow feed output signal is cancelled, the corresponding O2 relay is switched off. If the
parameter is set to both quick feed and slow feed ON, the slow feed output gives out a signal since
the beginning, and the corresponding O2 relay is closed until the weight reaches up to the slow feed
stop value A-C.
(3) Gradual feed-- If the parameter is set with gradual feed, the O2 relay corresponding to slow feed will
be closed for a period of t3, and switched off for a period of t4. Gradual feed is carried out through
such repeated cycle, until the weight reaches up to the allowance range of batching value, i.e. the
qualified area.
(4) Discharge-- Discharge output sends out a signal, and the corresponding O3 relay is closed. After the
weight is deducted from the value L in zero zone, the discharged is considered completed, which
corresponds to point M in the figure. At this moment, after another delay of t5, the discharge output
signal is cancelled, and the corresponding O3 relay is switched off. A complete control procedure is
finished.
Note: during the above process, if the slow feed lead is bigger than that of quick feed lead, i.e. C>b, then
the slow feed output won’t give out signal, and the corresponding O2 relay remains switched off. If no
gradual feed is set for parameters, the above gradual feed process (3) is not included. The turning off of
discharge should meet the conditions that the weight is less than zero zone value.
II. Mode 1(subtracting mode of 1 batching material)
Please refer to the following figure for understanding of the functions, meanings and time sequence of
control input and output of various parameters during the process:
Note: A—batching value; b—quick subtraction lead value; C—slow subtraction lead value;
t1—quick subtraction over delay;t2—slow subtraction over delay;t3—gradual feed output time;
t4—interval time of gradual feed;t5—discharge over delay
The schematic diagram of slow subtraction 1 shows the slow subtraction output when both the quick
subtraction and slow subtraction are ON during quick subtraction process, and gradual feed exists.
The schematic diagram of slow subtraction 2 shows the slow subtraction output when only the quick