Siemens S7-200 System Manual page 161

● DC digital inputs and outputs are isolated from logic circuit to 500 VAC.
● DC digital I/O groups are isolated from each other by 500 VAC.
● Relay outputs are isolated from logic circuit to 1,500 VAC.
● Relay output groups are isolated from each other by 1,500 VAC.
● AC power supply line and neutral are isolated from ground, the logic circuit, and all I/O to
Text Display (TD) User Manual
System Manual, 08/2008, A5E00765548-03
B.7 CPU Grounding and Circuit Reference Point Guidelines for Using Isolated Circuits
1,500 VAC.
Connecting Multiple Devices on a Network
161