Status Indicators Of The Isolators - Pepperl+Fuchs KCD2-SCS-Ex2.SP System Manual

K-System – Isolated Barriers
Product Specifications
2.5

Status Indicators of the Isolators

LEDs are often used on isolators to indicate different statuses (e. g. for power supply,
device failure, status messages, binary switching states). Standard LED colors are assigned
to the status display according to NAMUR NE44.
LED Display function
Green LED Power supply
Red LED Device fault, device failure
Line fault
No fault
Yellow LED Switching states of binary
inputs and outputs
Table 2.1 Meaning of status indicators
Figure 2.15
1 Yellow LED OUT
Switching state of the output
2 Red LED CHK
Lead breakage and short circuit status indicator
3 Green LED PWR
Power supply status indicator
16
Display
On
Off
On
Flashing
Off
On
Off
Example status indicators
Meaning
Power supply OK
No power supply or insufficient power supply –
device faulty
Internal fault signal, failure signal – fault/failure
display of causes detected inside the device,
device needs replacing
External fault signal, failure signal – fault/failure
display of causes detected outside the device,
inspection and elimination of fault required
No malfunction, device is operating properly
Possible causes of the output:
• The relay is energized.
• The NO contact (also a change-over contact)
is actively closed.
• The open collector is switched through.
• The switching voltage generated inside
the device is applied.
Possible causes of the input:
• A binary switching signal is present.
• An analog limit value is reached.
Possible causes of the output:
• The relay is de-energized.
• The NO contact (also a change-over contact)
is actively opened.
• The open collector is not switched through.
• The switching voltage generated inside
the device is not applied.
Possible causes of the input:
• A binary switching signal is present.
• An analog limit value is reached.
1 2 3
OUT CHK PWR