Siemens SINUMERIK 840D sl Manual page 191

Note
For machines that must be placed in a lower category (e.g. 1 or 2 in accordance with EN
954–1) based on the danger analysis / risk evaluation or type C standard, the control can in
general be derived from the provided typical circuit diagrams and constructed as a simpler,
single channel system structure!
This is also true for subareas/subfunctions of a machine, which, for example, in accordance
with the type C standards, must be constructed with a different lower or higher control
category than that of the base machine. For example, after the danger analysis / risk
evaluation it can also be necessary that a hydraulic/pneumatic clamping unit must be
controlled in the work area using a two-handed control device in accordance with category 4.
Note
All subsequent typical circuit diagrams do not contain any safety-relevant or other possible
machine-specific essential interlocks with the user-provided machine control.
Guide for the SINUMERIK 840D sl machine configuring
Manual, 07/2006 Edition, 6FC5397-6CP10-0BA0
7.2 Functional description of the typical circuit diagrams
Typical circuit diagrams
7-3