Siemens SIMATIC S7-1500 System Manual page 68

Wiring
5.8 Front connector for the I/O modules
Preparing and wiring front connectors for I/O modules without shield contact element
Proceed as follows to wire the front connector:
1. As needed, switch off the load current supply.
2. Place the included cable strain relief (cable tie) for the cable harness into the front
connector (Figure 1).
3. Swing the front cover of the wired I/O module up until the front cover latches (Figure 2).
Watch video sequence
(http://cache.automation.siemens.com/media/67462859_wiring_front_web_en/start.htm)
4. Bring the front connector into the pre-wiring position. To do this, hook the front connector
into the bottom of the I/O module and swivel the front connector upward until the front
connector latches (Figure 3).
Result: In this position, the front connector still protrudes from the I/O module (Figure 4).
However, front connector and I/O module are not yet electrically connected. By means of
the pre-wiring position, you can easily wire the front connector.
68
Automation system
System Manual, 12/2014, A5E03461182-AC