ABB AC500-S Safety User Manual page 323
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Also See for AC500-S:
- Safety user manual (452 pages) ,
- Application note (24 pages) ,
- System manual (119 pages)
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Based on Fig. 118, Fig. 119 and Fig. 120, the following exemplary SFRT values can be
achieved for some typical AC500-S configurations using
Without PROFINET (DI581-S ➔SM560-S ➔ DX581-S)
SFRT = Device_WD1 + 0.5 * F_WD_Time1 + F_Host_WD + 0.5 * F_WD_Time2 + Device_WD2
+ Longest ∆T_WD = 14.5 + 10 + 6 + 10 + 8 + 10 = 58.5 ms
where:
●
Device_WD1 = 1 ms + 0.5 ms + 2 x 6.5 ms = 14.5 ms (no test pulses were used)
●
F_WD_Time1 = 20 ms
●
F_Host_WD = 3 x 2 ms (SF_WDOG_TIME_SET time) = 6 ms
●
F_WD_Time2 = 20 ms
●
Device_WD2 = 8 ms (output current = ~ 5 mA)
●
Longest ∆T_WD = Max (0.5 * F_WD_Time1; 0.5 * F_WD_Time2) = 10 ms
Without PROFINET (DX581-S ➔ SM560-S ➔ DX581-S)
SFRT = Device_WD1 + 0.5 * F_WD_Time1 + F_Host_WD + 0.5 * F_WD_Time2 + Device_WD2
+ Longest ∆T_WD = 12.5 + 10 + 6 + 10 + 8 + 10 = 56.5 ms
where:
●
Device_WD1 = 1 ms + 0.5 ms + 2 x 5.5 ms = 12.5 ms (no test pulses were used)
●
F_WD_Time1 = 20 ms
●
F_Host_WD = 3 x 2 ms (SF_WDOG_TIME_SET time) = 6 ms
●
F_WD_Time2 = 20 ms
●
Device_WD2 = 8 ms (output current = ~ 5 mA)
●
Longest ∆T_WD = Max (0.5 * F_WD_Time1; 0.5 * F_WD_Time2) = 10 ms
2020/06/19
DANGER!
AC500-S safety I/O modules satisfy the requirement of IEC 61131 to bypass a
potential undervoltage event with a duration of up to 10 ms. During this under-
voltage effect of up to 10 ms, AC500-S safety I/O modules deliver the last valid
process value before the undervoltage was detected for safety analog input
channels in AI581-S and actual safety digital input and output values for DI581-
S and DX581-S modules.
If the undervoltage phase is longer than 10 ms then safety I/O module passiva-
Ä Chapter 3.2.3 "Undervoltage / overvoltage" on page 59.
tion occurs
If undervoltage events with duration of < 10 ms are frequently observed in the
safety application, you have to add 10 ms for AI581-S module in their SFRT cal-
culation to take into account a bypass stage described above. Normally, seldom
undervoltage events with duration of < 10 ms are considered to be low proba-
bility faults in the power supply of the safety system and can be omitted in the
SFRT calculation.
3ADR025091M0208, 12, en_US
Safety function response time
Ä Equation 2 on page 321:
Safety times
323
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