11.03
3 Safety-Related Functions
3.9 Safety-related input/output signals (SGE/SGA)
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
3-131
Table 3-54
Minimum SGE/SGA requirements
Function
Minimum SGE requirements
Minimum SGA requirements
Safe operating stop
(SBH)
SBH/SG de-selection
Test stop selection
Pulses cancelled status (NCK)
SBH/ SG active
Enable pulses (NCK)
Pulses cancelled status (drive)
Safely-reduced speed
(SG)
SBH/SG de-selection
SBH de-selection
SG selection, bit 1 (for SG changeover only)
SG selection, bit 0 (for SG changeover only)
Gear ratio selection, bit 2 (for ratio selection only)
Gear ratio selection, bit 1 (for ratio selection only)
Gear ratio selection, bit 0 (for ratio selection only)
Test stop selection
Pulses cancelled status (NCK)
SBH/ SG active
Enable pulses (NCK)
Pulses cancelled status (drive)
Safe software limit
switches (SE)
SE selection (for SE changeover only)
Test stop selection
Pulses cancelled status (NCK)
SBH/SG de-selection
(at least for test during start-up)
Axis safely referenced
Enable pulses (NCK)
Pulses cancelled status (drive)
Safe software cams
(SN)
Test stop selection
Pulses cancelled status (NCK)
SBH/SG de-selection
(at least for test when commissioning)
Axis safely referenced
SN1 -, SN2 -, SN3 -, SN4 -
(only if required)
SN1 +, SN2 +, SN3 +, SN4 +
(only if required)
Enable pulses (NCK)
Pulses cancelled status (drive)
The signal timing characteristics in the two monitoring channels varies (the PLC
cycle time takes up most of the available time in the drive monitoring channel).
To prevent the crosswise data comparison function from being activated
immediately after a signal change, a tolerance time is defined using the
following machine data:
For 840D MD 36950: $MA_SAFE_MODE_SWITCH_TIME
For 611 digital
MD 1350: $MD_SAFE_MODE_SWITCH_TIME
This data specifies the time period for which different signals states may be
tolerated after the SGEs have been changed over before an error message is
output.
Note
System-dependent minimum tolerance time:
2 x PLC cycle times (maximum cycle) + 1 x IPO cycle time
The variations in run times in the external circuitry (e.g. relay operating times)
must also be taken into account.
There are SGEs and SGAs for each axis/spindle (refer to Fig. 3-23 "SGEs and
SGAs in each monitoring channel for each axis/spindle").
The signals are assigned to the NCK inputs and outputs via machine data.
Only the NCK-SGEs are assigned to an NCK input that are also required for the
particular application.
For axes, where for example, the gear ratio does not change, the NCK SGEs
"ratio selection bit 2 to 0" do not have to be assigned HW inputs. A value of 0
should be entered into the associated MD (i.e. the NCK-SGE does not have a
hardware assignment and is set to 0).
Different signal run
times in channels
NCK SGEs/SGAs
