SPEED SYNC
233
11.1.5 SPEED SYNC
Application:
Cartons should be transferred from one conveyor belt (conveyor belt A), a belt operating at a very variable
belt speed, to another conveyor belt (conveyor belt C), a belt which has a constant belt speed. This task
should be performed using a transfer belt (conveyor belt B) installed between the two other belts. This belt
receives cartons from conveyor belt A and, when triggered by a pulse, passes them on to conveyor belt B. In
addition to this, when conveyor belt B is assigned, conveyor belt A should be blocked. Conveyor belt B is
activated using COMPAX.
Assignments:
light barrier
encoder
conveyor belt A
conveyor belt B
conveyor belt C
Function:
The first event after COMPAX has been started is the release of conveyor belt A. The system then waits until
the reflex light barrier (on I7) detects a carton (N003). Should a carton be received, the speed of conveyor
belt B is set to that of conveyor belt A (N004). This speed is recorded using an encoder on conveyor belt A
transmitting via the COMPAX encoder interface (channel 1). The positioning command (N005) now starts a
feed movement using the distance which is required to transfer the whole carton onto conveyor belt B. Since
the feed time is always the same as the speed of conveyor belt A, no errors occur due to slip between the
carton and one of the conveyor belts. Once the whole carton has been received, the system waits until I8
reports that the carton has been passed to conveyor belt C (N008). If, during this waiting time, another carton
arrives via conveyor belt A, this is blocked via O7. When the carton is passed on and conveyor belt A is
blocked, the speed of conveyor belt B is set to that of conveyor belt C (N010). The carton is transferred to
conveyor belt C at this constant speed using N011. Conveyor belt A is then released again (N002).
Programming:
Configuration:
Encoder input E2 option
P93 = +2
i.e. continuous operating mode
P98 = 314
i.e. travel per axis per encoder revolution = 314 mm
P143 = 4096 i.e. encoder pulse number = 4096
Names of the inputs and outputs:
I7
receive carton
0
#
no
1
#
yes
I8
deposit carton
0
#
no
1
#
yes
O7 conveyor belt A
0
#
block
1
#
release
List of programs:
N001: ACCEL 200.............................................. ;sets the acceleration and braking ramps
Transfer carton: ............................................ ;mark
N002: OUTPUT O7=1 ........................................ ;releases conveyor belt A
N003: IF I7=0 GOTO 3....................................... ;waits until carton is to be received
N004: SPEED SYNC.......................................... ;sets the speed to that on conveyor belt A
N005: POSR 360 ............................................... ;transfers the carton
N006: IF I7=0 GOTO 8....................................... ;queries whether carton is to be received
N007: OUTPUT O7=0 ........................................ ;blocks conveyor belt A
N008: IF I8=0 GOTO 6....................................... ;waits until carton is to be deposited
N009: OUTPUT O7=0 ........................................ ;blocks conveyor belt A
N010: SPEED 85 ............................................... ;sets the speed to that on conveyor belt C
N011: POSR 350 ............................................... ;deposits the carton
N012: GOTO transfers carton (2)....................... ;goes to data record N002
