Owner manual
LOGIC
5-317
Chapter 5
Dual channel safety input
This function is for connecting a safety device with a dual channel solid state output (PNP output),
such as a safety light curtain or a safety laser scanner, or a safety device with contacts such as an
emergency stop switch or an interlock switch. As shown in Fig. 5-7, this function is comprised of a
dual channel receive circuit (X
n
, X
n+1
) and a functional output (I
n
). Use safety devices with
diagnostic functions or prevent the short circuit of an input circuit. Because the drive circuit is not
used for this function.
-For safety device with dual channel solid state output (PNP out put)
-For safety device with contacts
Fig. 5-7 Circuit for dual channel safety input function
Connects to
Safety devices with dual channel solid state outputs (PNP output), such as safety light curtains or
safety laser scanners, or safety devices with contacts such as emergency stop switches or
interlock switches.
Warning
Safety performance depends on used safety devices.
Mechanical contact devices, such as emergency stop switches or interlock switches, cannot be
connected.
Note. Solid state output devices with sink outputs (NPN output) cannot be connected.
Description of operation
The operation timing is described in Fig. 5-8.
I
When the dual channel safety check signals from the safety device are correctly supplied to
the 2 input receiving circuits, the output is turned ON. (Ex. Safety light curtain is not shaded.)
II
When the safety check signal to either of the receiving circuits is turned OFF, the output is
turned OFF immediately. (Ex. Safety light curtain is shaded.)
III
If safety check signals are not supplied correctly to the input receiving circuits, due to an error
in the safety device or input circuit, the output is turned OFF immediately. Status of the
detected error is displayed by the error LED, input LEDs and monitor output. (Ex. Fault in
the light curtain or wiring)
X
n
X
n+1
Safety device
I
n
V+
V-
Dual Channel Safety
X
n
X
n+1
I
n
V+
V+
Dual Channel Safety
Safety device