Siemens SIMATIC S7 - Page 150

Technical specifications
A.2 Fail-Safe CPU technical specifications
S7-1200 Functional Safety Manual
150 Manual, 02/2015, A5E03470344-AA
Technical data
Description
Time delay interrupts
4 total with 1 ms resolution
Cyclic interrupts 4 total with 1 ms resolution
Edge interrupts
12 rising and 12 falling (16 and 16 with optional signal board)
Memory card SIMATIC Memory Card (optional)
Real time clock accuracy
+/- 60 seconds/month
Real time clock retention time
20 days typ./12 days min. at 40 °C (maintenance-free Super Capacitor)
1
The slower speed is applicable when the HSC is configured for quadrature mode of operation.
2
For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.