Siemens SIMATIC ET 200SP Manual page 31

Parameter
4.3 Substitute value behavior
The "current-free/voltage-free" behavior takes effect in the following cases:
• Incorrectly configured module
• Module with incorrect parameter assignment
30
Interface Module IM 155-6 PN R1 (6ES7155-6AU00-0HM0)
Equipment Manual, 11/2022, A5E51160307-AA