11.03
4 Data Descriptions
4.1 Machine data
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
4-223
36944
MD number
$MA_SAFE_REFP_POS_TOL
Actual value comparison tolerance (referencing)
840D
Default: 0.01 mm
Min. input value: 0
Max. input value:
1 mm or 36 degrees
Change becomes effective after POWER ON:
Protection level (R/W) 7/2
Unit: mm, inches, degrees
Data type: DOUBLE
Applies from SW 3.4
Meaning
The tolerance for the actual value check after referencing (with an incremental encoder)
or at POWER ON (with an absolute encoder) is set in this data.
A second absolute actual position is calculated from the last standstill position that was
saved prior to control power off and the distance traversed since POWER ON. The control
system checks the actual values after referencing on the basis of the two actual positions,
the traversed distance and this data.
The following factors must be taken into consideration when calculating tolerance values:
Backlash, leadscrew errors, compensation (max. compensation values for LEC, sag and
temperature compensation), temperature errors, torsion (2-encoder system), gear play for
selector gearboxes, lower resolution (2-encoder system), oscillating distance for selector
gearboxes.
Special cases, errors
If these two actual positions deviate from one another by more than the value set in this
data with valid user agreement, then Alarm 27001 is displayed with error code 1003 and a
new user agreement is required for referencing.
36946
MD number
$MA_SAFE_VELO_X
Speed limit n
x
840D
Default: 20.0
Min. input value: 0.0
Max. input value: 1 000.0
Change becomes effective after POWER ON:
Protection level (R/W) 7/2
Unit: mm/min
inch/min, rev./min
Data type: DOUBLE
Applies from SW 4.2
Meaning
This data defines limit speed n
x
for SGA "n < n
x
".
Corresponds with …
MD 1346: $MD_SAFE_VELO_X
References
Refer to Chapter 3, "SGA "n < n
x
" and "SG active""
36948
MD number
$MA_SAFE_STOP_VELO_TOL
Actual speed tolerance for SBR
840D
Default: 300.0
Min. input value: 0.0
Max. input value: 20 000.0
Change becomes effective after POWER ON:
Protection level (R/W) 7/2
Unit: mm/min
inch/min, rev./min
Data type: DOUBLE
Applies from SW 4.2
Meaning
After the safe braking ramp has been activated, the actual speed plus the speed tolerance
set in this machine data are applied as a speed limit.
Corresponds with …
MD 1348: $MD_SAFE_STOP_VELO_TOL
References
Refer to Chapter 2, "Safe braking ramp (SBR)"
(a recommended setting and setting formula are specified in this Chapter).
36949
MD number
$MA_SAFE_SLIP_VELO_TOL
Speed tolerance slip
840D
Default: 6.0
Min. input value: 0.0
Max. input value: 1000.0
Change becomes effective after POWER ON:
Protection level (R/W) 7/2
Unit: mm/min
inch/min, rev./min
Data type: DOUBLE
Applies from SW 5.2
Meaning
Speed difference that, for a 2–encoder system is tolerated between the drive and and
load sides without the crosswise data comparison between SIMODRIVE 611digital and
NCK signaling an error.
MD 36949 is only evaluated if MD $MA_SAFE_FUNCTION_ENABLE, bit 3 is set.
Corresponds with …
MD 1349: $MD_SAFE_SLIP_VELO_TOL
References
Refer to Chapter 3.11.4, Actual value synchronization
