Safe Software Cams (Sn) - Siemens SINUMERIK 840D Description Of Functions

11.03

3.7 Safe software cams (SN)

Description The "safe software cams" function (SN) can be used to implement safe
electronic cams, a safe range detection or limiting the working zone/protective
zone for specific axes, thereby replacing the hardware solution.
There are four pairs of cams (SN1, SN2, SN3, SN4) available for each axis.
Each cam pair consists of a plus cam (SN1+, SN2+, SN3+, SN4+) and a minus
cam (SN1-, SN2-, SN3-, SN4-). Each cam signal can be individually enabled
and configured via machine data. The cam signals are output via SGAs.
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Function features The most important features include:
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Prerequisites The following prerequisites must be fulfilled for the "safe cams" function:
The axis/axes must have been safely referenced (user agreement)
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© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
Important
The enabled cam signals are immediately output when the control system is
pwered-up, but are only safe after safe referencing (signaled via the SGA
"axis safely referenced").
For safe evaluation of the cam signals, the SGA "axis safely referenced" must
be taken into account.
Safe definition and evaluation of cam positions as a software function
Definition of working ranges/zones
The safe cams must be configured:
The required cams are enabled using MD
$MA_SAFE_FUNCTION_ENABLE, bit 8...15
The cam positions are defined using MD
$MA_SAFE_CAM_POS_PLUS[n] and
$MA_SAFE_CAM_POS_MINUS[n]
SGA assignment is defined using MD
$MA_SAFE_CAM_PLUS_OUTPUT[n] and
$MA_SAFE_CAM_MINUS_OUTPUT[n]
3 Safety-Related Functions
3.7 Safe software cams (SN)
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