2
0
1
8
-0
6
34
Operating Behavior
4
Operating Behavior
4.1
Switch-On Behavior
In the operating modes "Standard ZPA," "Enhanced ZPA," and "Long Zone," the ZPA motor
control module waits for the duration of the switch-on delay after the power supply is switched
on before it is ready for operation. The only exception is the output of the status of the zone
sensor at the relevant interface for zone coupling (X1 or X2). This signal is present 1 s after
switch-on.
After the switch-on delay, the ZPA motor control modules of the individual zones start searching
for conveyed product that might be lying undetected between the zone sensors. The search
ends as soon as conveyed product is detected at the zone sensor or once the search time has
passed. The switch-on delay randomly delays the start of the search for a ZPA motor control
module. This is done to prevent current peaks caused by the simultaneous activation of the DC
roller motors at all ZPA motor control modules whose zone sensor did not detect any conveyed
product.
While the ZPA motor control module is starting up, the LEDs indicate the firmware version and
the setting of the rotary switches using flash codes. Details can be found in the Chapter
"Indicators and Operating Elements."
4.2
Switch-On Delay
The switch-on delay is the time that a zone waits after startup before resuming normal
operation. The time is randomly selected in the range 2 ... 5 s by the ZPA motor control module.
4.3
Search Time
Search time = 4 s
If there is no conveyed product in front of the zone sensor after startup or if conveyed product
was unexpectedly removed from the zone sensor during normal operation, the search time will
begin.
During this time, the zone will search for conveyed product that might lie undetected between
its sensor and the upstream zone sensor. For this purpose, it switches the motor on and waits
for conveyed product to reach the zone sensor. Once the search time has passed, the zone will
assume that it is empty and continue with normal operation.
In the operating mode "Standard ZPA," the release signal is set during the search time only if
conveyed product is located in front of the zone sensor of the upstream zone. Because the
zone is not able to detect whether the conveyed product is still completely in the upstream zone
or partially extends into the zone itself, it sets the release.
In the operating mode "Enhanced ZPA," the release signal is always set during the search time
to ensure a rapid startup of the conveyor line. If conveyed product is detected at the zone
sensor during the search time, the zone will continue normal operation. After the conveyed
product has been conveyed out, the zone begins to search again to make sure that no
conveyed product remains undetected between the zone sensors.
4.4
Leaving time
Leaving time = 8 s
The leaving time is the time it takes for conveyed product located in front of the zone sensor to
move away from this sensor after the motor has been switched on.
If the conveyed product requires longer than the leaving time, the zone will assume that there is
an accumulation. It shuts down its motor and resets the release signal. The zone will resume
normal operation once the blocked conveyed product is manually removed from the zone
sensor. Immediately after that, the search time begins again.
