7.2.9 Error Reaction Times
The following table provides the maximal error reaction times of the system:
Item
Description
Time
I/O Discrepancy
The safe digital inputs and input are checked for consistency. If a discrepancy is present between the two
channels, which stays longer than the indicated time, an error will be generated (Safe Input Fault or Safe
Output Fault).
50 ms
Safe Encoder
Discrepancy
The two MCU on the safety module check periodically the evaluated position. If a discrepancy occurs the
"Encoder fault" error is generated and the drive activates STO.
10 ms
Safe Encoder Signal
Error
If the sine and cosine signals are not consistent (invalid combination) the "Encoder fault" error is
generated and the drive activates STO.
5 ms
Safe Brake Control
Error
The safe brake control is checked periodically with test pulses. In case of an error "Brake output fault" is
generated and the drive activates SS1.
5 s
Table 26: Error reaction times
7.2.10 System Reaction Times
The following table provides the maximal reaction system reaction times:
Item
Description
Time
Safety Function
Reaction Time
Digital IO
The reaction time from the safety function request via safe digital input to the feedback on the
safe digital output.
Note: for some safety functions there may be additional delay times to be regarded.
30 ms
Safety Function
Reaction Time over
Bus
The reaction time from the safe bus control word request to the feedback on the safe bus status
word.
Note: for some safety functions there may be additional delay times to be regarded.
20 ms
Safety Function
Reaction Time Bus
IO combined
The reaction time from request to feedback when one signal is via safe digital I/O and the other
via safe bus.
Note: for some safety functions there may be additional delay times to be regarded.
30 ms
Acknowledge Edge
Distance
The minimal edge distance on the acknowledge signal.
12 ms
SOS Position Error When the position deviation exceeds the position tolerance (UPID 47E2h), the configured error
reaction is done. The position evaluation is done every millisecond.
5 ms
SLS Speed Error
If the speed, watched in SLS exceeds the limit an error is generated. The speed evaluation
depends on the parameter speed computation time (UPID 47A3h) and for generating the fault
reaction additional 5 ms must be calculated.
5 ms + Speed
Computation Time
Brake Activation
The activation time of the brake mainly depends on the valve and the brake itself.
The time between activation (via safe digital input or bus) and the switching of the brake output,
maximal 20 ms will pass.
For the configuration of 47D5h “SBC STO_Delay” consider the switching characteristics of the
value and brake.
20 ms + physical
brake delay
Table 27: System reaction times
2S Drive Systems / 0185-1174_E_1V1_SM_C1251-2S / NTI AG
0185-1174_E_1V1_SM_C1251-2S / 2021-11-26 16:43 (Rev. 12500)
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