Safe Software Limit Switches (Se) - Siemens SINUMERIK 840D Description Of Functions

11.03

3.6 Safe software limit switches (SE)

Description The "safe software limit switch" (SE) can be used to implement protective
functions for operating personnel and machinery or limiting the working
zone/protective zone for specific axes. For example, this function can replace
hardware limit switches.
Two safe software limit switches (SE1 and SE2) are available for each axis.
If the "SE" function is active, limit switch position pair SE1 or SE2 can be
selected as a function of SGE "SE selection".
Defining upper and The position limit values for limit switch position pairs 1 and 2 are defined in the
lower limit values following machine data:
For 840D
For 611 digital
Function features The most important features include:
Safe definition and evaluation of software limit switches as a software function
Configurable stop response when software limit switches are actuated
The stop response is implemented internally in the software (and is therefore
faster than a hardware limit switch response) when software limit switches are
passed (actuated).
Prerequisites The "safe software limit switch" function is dependent on the following
prerequisites being fulfilled (refer to Chapter 2.8, "System prerequisites"):
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SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
MD 36934: $MA_SAFE_POS_LIMIT_PLUS [ n ]
MD 36935: $MA_SAFE_POS_LIMIT_MINUS [ n ]
MD 1334: $MD_SAFE_POS_LIMIT_PLU [ n ]
MD 1335: $MD_SAFE_POS_LIMIT_MINUS [ n ]
Note
The upper and lower position limit values must be selected so that when the
axis is traversing in this direction the software limit switches that are used as
standard are first reached.
The "safe software limit switch" function must be enabled
The axis/axes must have been safely referenced (user agreement)
SGE "SE selection" must be provided (configured) in both channels.
Warning
The "safe software limit switches" are only effective if the user agreement has
been given.
3 Safety-Related Functions
3.6 Safe software limit switches (SE)
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