Only one SI Basic and one SI Comfort option can be ordered for each SINUMERIK 840D sl NCU. If a machine with Safety Integrated requires up to 4 safe inputs and 4 safe outputs, the SI Basic option can be ordered. If 5 or more safe inputs/outputs are required, the SI Comfort option should be ordered.

Ordering example 1:
The machine has 2 axes and 1 spindle, which are to be monitored by Safety Integrated. 4 safe inputs and 3 safe outputs are required. The following options must be ordered:

Ordering example 2:
The machine has 5 axes and 1 spindle, which are to be monitored by Safety Integrated. 9 safe inputs and 5 safe outputs are required. The following options must be ordered: