■ Wiring example 4
One-channel connection. This connection is SIL1 capable (no
redundancy between STO channels).
11
12
21
22
XSTO1
PTC
XSTO
T1 T2
XFLT
FPTC
OUT
SGND
IN1
IN2
SLOT
1/2/3
X100
XSTO2
3 ~
Ex M
a)
1
2
Control unit1
Potentially explosive atmosphere2
a) If necessary, you can connect an external device (eg, an
emergency stop button) between the XSTO input of the control unit
and the XSTO2 output of the FPTC module.
46 Electrical installation