FI002K0018v1530hUK – THS/21 Instruction manual for installation, use and maintenance
3
INSTALLAZIONE
ORIGINAL
INSTRUCTION 139
3.10.6 EM = FS
Photocell at the exit (PH=OUT)
Generic example
S: Metal Detector Probe
N: Conveyor belt
A: Air jet ejector
F1: Synchronization photocell
F2: Ejection check sensor
PL: Pack length
DW: Detector width
ED: Ejection distance
PD: Photocell distance
ECPD: Photocell distance
Waveform
Description
Signal over the alarm threshold
with transport activated
Metal alarm
PHOTOCELL
-
ALARM RELAY
External alarm signalling
EJECT RELAY
Ejection signal for the complete
removal of the area
R
(or
Re
)
YELLOW LAMP
Alarm beacon operation
AT = Minimum activation time of the alarm relay;
t1 = Alarm time, generally corresponding to the transit of the metal mass through the Probe.
a = Calculated automatically to activate the ejector at the start of the removal area R or Re;
b = Calculated automatically for the complete removal of area R or Re (alarm time + time needed for the complete
removal).
The effective removal area
Re
is determined through the Sinchronization photocell, setting EE and ES to a value at least
equal to PL. This area is necessary to grant a correct ejection in case of product across the beginning and the end of the
removal area set (R). Setting EE=ES=0, the removal area will always be equal to R.
E:
Ejected pack;
C:
Contaminated and ejected pack;
EE:
Ejection end synchronization area;
ES:
Ejection start synchronization area
R:
Minimum removal area = DW+2PL
Re:
Actual removal area = R+x+y
For more accurate adjustment of the delay in activating and deactivating the ejector, early and delayed activation can be
adjusted based on the actual response time of the ejector. See the parameters ERT and ERF.
ALARM RELAY and YELLOW LAMP can be programmed to stay activated, after an Alarm, until a manual reset
(parameter AT)
