Siemens SINUMERIK 840D Description Of Functions page 173

11.03
3.11 Encoder mounting arrangements
Previous history The previous history consists of the saved user agreement and the saved
standstill position (refer to "Saved user agreement" and "Saved standstill
position").
As described under "Axis safely referenced", a previous history can be used to
obtain the axis state "axis safely referenced".
The following conditions must be fulfilled:
•
•
SBH/SG
is reliable
from this
Axis status
axis status
EQN: Read absolute value from encoder
ERN: Approach reference point
Axis status
Check OK
SE/SN
is reliable
Axis status
from this
axis status
Fig. 3-43 Axis states during referencing
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
The saved user agreement must be available.
The difference between the "reference position" (power on position with
absolute measuring systems or reference position with incremental
measuring systems) and the saved standstill position (including traversing
distance to reference point with ERN) must be within a tolerance window
specified via machine data.
Axis not
referenced
Axis
referenced
no
Previous
history
yes
Internal
Check
check of
previous
not OK
history
Axis safely
referenced
3 Safety-Related Functions
Axis status is displayed via:
Interface signal
"Reference point reaced" = "0"
Interface signal
"Reference point signal" = "1"
Check of position
JUST_01.DSF
User agreement
(softkey)
SGA
"Axis safely referenced"
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