Siemens SINUMERIK 840D Description Of Functions page 60

3 Safety-Related Functions
3.1 Basic mechanisms of SI functions
Start
Timer
"Pulses
disabled
status"
STOP A
NCK CPU
Fig. 3-3 Shutdown path of the NCK CPU via terminal 663
Safe internal pulse Internal pulse cancellation can only be used together with the 611 digital
cancellation modules High Performance and High Standard. Terminal 663 must then be
(SW 6.3.30 and higher) wired to the SGA "externally enable pulses". Whether or not the pulses were
successfully cancelled can be returned internally. This considerably reduces
the number of NCK I/Os required.
Fig. 3-4 shows the sequence when canceling pulses. Internal pulse canceling is
initiated via the NCK SGE "test stop selection" (can also be initiated internally
as STOP A). The comparator internally cancels the pulses via the drive bus.
The status is internally read back via the drive bus. If the pulses were not
successfully cancelled, then the enable from module-specific terminal 663 at
the 611 digital drive module is withdrawn using the SGA "externally enable
pulses". The SGEs/SGAs are assigned to the NCK HW inputs/outputs via
machine data.
The local NCU inputs and outputs can be used to externally cancel the pulses
(NC onboard-IOs, refer to Chapter 3.10.2). Terminals 663 of all of the drives or
a group of drives would be controlled via such an output.
3-60
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
SGE Test stop selection
SGE "Pulses are disabled status"
Inputs
Enable SGA pulses
Outputs
"Drive_IMP"
relay
Drive bus
Drive closed-loop control
Note
To set up the shutdown path for the NCK CPU, the machine manufacturer
must provide external wiring for the axis-specific drive terminals 663 and
AS1/AS2.
From NCK software version 6.3.30 onwards, the pulse enable signal can be
returned (terminal AS1/AS2) internally for all of the control modules.
(via NCKI/O devices)
+24V
AS1
Terminal 663
+5V
0V
Safety
relay
0V 0V
ABSCH_02.DS4
© Siemens AG 2003 All Rights Reserved
11.03
AS2