Siemens SINUMERIK 840D sl Equipment Manual page 93

If an emergency stop is triggered, the button locks into place.
If the button is locked into place, it can be unlocked by rotating it to the right.
The signals are sent via the connecting cable to the terminal box or the connection module
and are available for further wiring.
Rotary override switch
The rotary override switch of the HT 8 has 19 positions.
The evaluation scale (0 to max.) is specified by the machine's manufacture in the form of
machine data.
Enabling button
The HT 8 has two enabling buttons that are logically grouped.
This allows the enabling function to be triggered by either the left or the right hand during
normal operation.
The enabling buttons are configured as 2-channel, 3-position switches for the following
button positions:
• Released (no activation)
• Enabling (center position) - enabling for channel 1 and 2 is on the same switch.
• Panic (completely pushed through)
Note
Monitoring the enabling function
• The enabling duration is monitored to avoid that the enabling button is permanently
bypassed. The enabling outputs are opened after max. 30 min permanent enabling. The
enabling outputs are only closed again after first releasing the enabling button and then
actuating it again. The enabling time of 30 min can be extended by switching to the second
enabling button before the 30 min expires.
• The system checks the synchronism of the two enabling button circuits of the mechanical
enabling button. The two enabling button circuits (of the button) must be closed within 2
seconds. As a consequence, it is not possible to actuate just one enabling circuit and
therefore provoke a fault.
Handheld Terminal HT 8
Equipment Manual, 02/2024, A5E52918633B AA
Emergency Stop button
Press the red button in emergencies when
∎
∎
As a rule, when operating the Emergency Stop button, all
drives are brought to a standstill with max. braking torque.
Machine manufacturer
For other responses to the Emergency Stop:
Refer to the machine tool manufacturer's instructions!
Operator control and display elements
people are at risk,
there is the danger of machines or the workpiece being
damaged.
5.2 Description
93