Technical data’s and circuit diagrams for the modular system
PCD0
26/766 E2
(HB_PCD0 26 766_E2.DOC)
SAIA-Burgess Controls Ltd.
Page 97
4.19.3
Functions
Every up/down counter counts the pulses of an incremental encoder
(it is not possible to connect absolute value encoders). The counter
value is compared with two threshold values thus allowing to control
an axis.
The movement of the axis is stopped independently from the counting
procedure by the limit switch inputs. The counters can be configured
in the PLC. The PLC can write in configuration memories, threshold
and counter values and read counter values and input/output states
with the exception of tracking signals A, B.
·
Counting
method:
Periodical,
·
when maximum has been reached the counter continues at the minimum value, when minimum
has been reached counter continues at maximum
·
Counting frequency:
up to 200 kHz
·
Width:
32
bits
·
Range:
-2
31
to 2
31
-1
·
Edge
evaluation:
4-fold
·
Setting on the PLC:
Mode, homing direction, homing speed, using N for homing, select outputs, reset counter,
counting direction inverted, motion direction outputs inverted, speed output inverted, counter
value, pre-shutdown value, shutdown value, override for inputs/outputs
·
Setting on the bus coupler
Overwrite inputs/outputs with FORCE/LOCK
·
Storage of data:
Data or configurations will not be saved if there is a power cut.
·
DC 24 V signal level for input and output signals
·
Inputs:
Tracking signals A, B and N, End+, End-
·
Outputs:
Move+, Move-, Speed
can be switched to: Direction, Move, Speed
Operating modes
Homing 1
st
variation (feed positioning)
Fast (default; can be changed to slow) in homing direction until End+
or End- active. Then slowly in the opposite direction until N is active.
Reset counter and turn off.
Homing 2
nd
variation (feed positioning)
Fast (can be changed to slow) in homing direction until End+ or End-
active. Then slowly in the opposite direction until the limit switch is no
longer active. Reset counter and turn off.
Homing 3
rd
variation (band positioning)
Fast (can be changed to slow) in homing direction. After End+ on 24 V
(i.e. alternative use of this limit switch) until N is active. Reset counter
and turn off. The PLC is notified when homing is completed.
Positioning:
Fast until pre-shutdown threshold, slowly until shutdown threshold,
then turn off.
The PLC is notified when positioning is completed.
Positioning 2
nd
variation (measurement of distance after zero pulse)
