Technical specifications
A.2 Fail-Safe CPU technical specifications
S7-1200 Functional Safety Manual
164 Manual, 02/2015, A5E03470344-AA
Table A- 34 Digital outputs
Solid state - MOSFET (sourcing)
5 to 30 VDC or 5 to 250 VAC
Logic 1 signal at max. current
Logic 0 signal with 10 KΩ load
Leakage current per point
Required external overload protection
4
10 A maximum must be limited to any
5 A maximum must be limited to any
Isolation (field side to logic) 1500 VAC for 1 minute (coil to contact)
500 VAC for 1 minute
Isolation between open contacts
Isolation (group-to-group)
1
Inductive clamp voltage -- L+ minus 48 VDC,
Switching delay (Qa.0 to Qa.3) 10 ms max. 1.0 μs max., off to on
3.0 μs max., on to off
Switching delay (Qa.4 to Qb.1) 10 ms max. 50 μs max., off to on
Maximum relay switching frequency
Pulse Train Output rate Not recommended
2
100 kHz (Qa.0 to Qa.3)
3
, 2 Hz min.
3
Lifetime mechanical (no load)
10,000,000 open/close cycles
Lifetime contacts at rated load
100,000 open/close cycles
Last value or substitute value (default value 0)
Number of outputs on simultaneously
10 outputs at 55 °C horizontal or 45 °C vertical
500 m shielded, 150 m unshielded
Relay group-to-group isolation separates line voltage from SELV/PELV and separates different phases up to 250 VAC
line to ground.
For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.
Depending on your pulse receiver and cable, an additional load resistor (at least 10% of rated current) may improve
pulse signal quality and noise immunity.
4
External overload protection is to limit fire hazard. Overload can damage relay or transistor output.