NORD Drivesystems BU0230 - Manual (Page 59)

5 Protective switching devices
BU 0230 GB-2712 59
5.3 OSSD outputs, test pulse

t
off
≤ 0.5ms (width of test pulse)
Maximum time for which the output of the safety switching device is switched off for test purposes.

D ≥ 90% (Duty)
The supply voltage is applied for at least 90% of the time. I.e. for a test pulse of t
off
=0.5 ms the supply
voltage is subsequently applied for at least t
on
=4.5 ms.

Double pulses are permitted when the two pulses are at least 1ms apart and the condition for D is
observed.
zulässige Testpulse eines OSSD
0
1
-1 0 1 2 3 4 5 6 7 8 9 10 11
Zeit in ms
The following sequence results at maximum pulse width: First test pulse, where t
off
= 0.5 ms, the supply
voltage is then connected for 0.5 ms, followed by the second test pulse where t
off
= 0.5 ms, and then the
supply voltage is connected for at least 8.5 ms!
Permissible test pulses for an OSSD
Time in ms