OSSD

Test pulses on safe digital inputs (SIN1 to SIN4)

The Safety Controller used must be compatible with OSSD (Output Switching Signal Device) according to IEC 61496-1.

Safety controllers check their outputs periodically during normal operation. Their self-test processes create pulses to the safe inputs of the drive.

Timing	Min	Max
T1	150 µs	1 ms
T2	100 ms	1 s
T3	> T1 (non-overlapping)

Test pulses with 150 µs ≤ T1 ≤ 1 ms and T2 ≥ 100 ms will not have any influence on the safety function. Test pulses, which are outside of this specification, will switch the safety function but will not create a dangerous situation.

The SMM software enters the I/O Failure State (fault reaction time ≤ 2ms)

if no test pulse is detected for a period of 5 seconds,
if three test pulses on different channels overlap three times in succession.

With Safety Option 1 test pulses are ignored.

Test pulses on safe digital outputs (SOUT1 to SOUT4)

The safe digital outputs can be used as 24 V source voltage to be switched by an external safety relay to STO inputs.

Timing	Min	Max
T1	450 µs	550 µs
T2	810 ms	990 ms
T3	> T1 (non-overlapping)

The output test pulses are compatible with the safe digital input requirements. There is only one test pulse on all four outputs at a time. They do not overlap each other. Be sure to use a force-guide relay, converter, or controller that does not respond to these test pulses.