Controlling the safety functions   
7.3 Control of "STO" and "SS1" via terminals on the Control Unit and the Motor/Power Module 
  Safety Integrated 
174  Function Manual, 05/2010, A5E03264275A 
 
NOTICE 
 
An open input is interpreted as "low". 
To enable the digital inputs (DI) to function, terminal M2 must be connected. 
This is achieved by: 
1.  Providing the ground reference of the digital inputs, or 
2.  a jumper to terminal M. 
Caution! This removes the electrical isolation for these digital inputs. 
 
 
Note 
If a momentary interruption in the voltage occurs in the 24 V supply, the digital outputs will be 
deactivated until the interruption has been rectified. 
 
Wiring 
The control lines must be permanently laid. 
Signal cables and encoder cables should be installed separated from one another. 
The shields of the control lines must be wide-area grounded directly after entry into the 
control cabinet. 
Outside the control cabinet the cables must be laid in such a way that they are safe to walk 
on (e.g., conforming to IEC 60204-1).