GB
7
2.3.4) Connecting the photocells
This control unit features a “Phototest” function designed to improve
the reliability of the safety devices, enabling the control unit and safe-
ty photocells set to fall under “Category 2” according to EN 954-1
(12/1998 edition).
Each time a manoeuvre is started, the safety devices involved are
checked; the manoeuvre is started only if everything is OK. If the test
does not have positive results (photocell blinded by sun, shorted
cables, etc.) the fault is identified and the manoeuvre is aborted.
To obtain the “Phototest” function you need to:
• Connect the photocells as shown in
fig. 4a
(when using a single
pair of photocells) or in
fig. 4b
(when using two pairs of photo-
cells). The power supply to the photocell transmitters is not drawn
directly from the service output but from the “Phototest” output
between terminals 10-12. The maximum current available from the
“Phototest” output is 100mA.
• Power the receivers directly from the service output of the control
unit (terminals 17-18).
• Set Dip –Switch 10 to ON: Phototest enabled; in the future it can
be disabled at any time by setting Dip –Switch no. 10 to OFF: Pho-
totest disabled.
When using 2 pairs of photocells which may interfere with each oth-
er, activate the synchronisation function as described in the photo-
cell instructions.
A traditional photocell connection, such as that shown
in fig. 4c, will not enable the use of the “phototest” func-
tion.
!
11
11
11
10
10
10
16
12 13
15
14
1
18
17
19 20
1
FOTO
TX
2
2
1
2
1
2
1
16
16
12 13
15
14
12 13
15
14
1
18
17
19 20
18
17
19 20
FOTO B
FOTO A
TXB
2
TXA
1
2
FOTO
2
TX
1
2
RxA
RxB
2
1
RX
5
3 4
5
3 4
11
10
10
12
1
2
TX
RXB
5
RXA
3 4
3 4
5
RX
12
10
TXB
TXA
1
2
12
10
1
2
TX
5
4
2
1
3
RX
10
13
17
FOTO
11
5
17
11
10
3
2
1
4
5
RX
13
FOTO B
5
FOTO A
11
10
RXB
3
2
1
4
5
RXA
13
17
11
10
FOTO
3 4
5
1
2
fig. 4a
Connection of a pair of
photocells enabling
the use of the
photocell function
fig. 4b
Connection of two
pairs of photocells
enabling the use of
the photocell function.
The photocells are
connected to enable
the activation of the
synchronism.
fig. 4c
Connection of a pair of
photocells that will
NOT enable the use of
the photocell function
