Explanation of the typical system times
108366_en_01
PHOENIX CONTACT
A 2
Explanation of the typical system times
Switch-on delay
The sensor performs a self-test when the operating voltage is switched on. Only after this
time is the safety switch ready for operation.
Switch-on time of the safety outputs
The maximum switch-on time of the safety outputs applies starts when the actuator is in the
response area and ends when the safety outputs are switched on.
Synchronous activation monitoring of the safety inputs
If the safety inputs have a different switching state over a certain time, the safety outputs are
switched off. The safety switch changes to the error state.
Risk time according to EN 60947-5-3
(Description adapted)
If the actuator leaves the response area of the sensor, the safety outputs are switched off
when the risk time has elapsed at the latest.
If several safety switches are operated in a series connection, the risk time of the entire
switch chain increases with every additional device.
Use the following formula to calculate the risk time for a switch chain:
Discrepancy time
The safety outputs are switched at a slight offset. The safety outputs have the same state
as soon as the discrepancy time has elapsed at the latest.
Test pulses on the safety outputs
The safety outputs generate test pulses:
–
When switched on
–
When switched off during device startup
Downstream devices have to tolerate these test pulses.
The values for the typical system times can be found in the technical data.
See “Times” in Section “Technical data” on page 57.
t
r
= t
r,e
+ (n x t
l
)
t
r
= Total risk time
t
r,e
= Risk time of an individual device (see technical data)
t
l
= Risk time delay for each device (see technical data)
n
= Number of additional devices (total number - 1)