Siemens S7-300 - Page 322

Response times
D.1 Response Times
Fail-safe signal modules
322 Installation and Operating Manual, 01/2010, A5E00085586-10
Response time of SM 326; DO 10 x DC 24V/2A
Calculation of the response time of SM 326; DO 10 x DC 24V/2A (without active error and
with active error):
Response time = internal signal preparation time + output delay
The output delay can always be ignored.
Example SM 326; DO 10 x DC 24V/2A in safety mode:
Response time = 24 ms + 0 ms = 24 ms
Note
Calculate the maximum response time by inserting the maximum values derived from
technical data of the fail-safe signal modules in the formula shown earlier.
Maximum response time of SM 326; F-DO 10 x DC 24V/2A PP
Calculation of the response time of SM 326; F-DO 10 x DC 24V/2A PP (without active error
and with active error):
Response time = 2 × internal preparation time + MAX{ max. read-back time dark
test, max. light test time } + 10 ms
Example SM 326; F-DO 10 x DC 24V/2A PP in safety mode:
Response time = 2 × 8 ms + MAX{1 ms, 0.6 ms} + 10 ms = 27 ms
Note
Calculate the maximum response time by inserting the maximum values derived from
technical data and the configuration of the fail-safe signal modules in the formula shown
earlier.