Siemens SINUMERIK 840D Description Of Functions page 117

11.03
3.7 Safe software cams (SN)
Fig. 3-20
Output assignment The status of the individual cams is indicated via SGAs SN1+, SN2+, SN3+,
for SN SN4+ and SN1-, SN2-, SN3-, SN4-.
In the NCK monitoring channel, the NCK SGAs are assigned to output
terminals via the following machine data:
For 840D
In the drive monitoring channel, the PLC SGAs are mapped in the NC/PLC
interface (refer to Chapter 4, "Interface signals") and output via the PLC I/O by
the PLC user program.
Modulo display of safe The modulo display of the safe actual value is selected and parameterized for
actual value rotary axes using the following machine data:
(840D, SW4.2 and
MD 30300: $MA_IS_ROT_AX
higher)
MD 30320: $MA_DISPLAY_IS_MODULO
MD 30330: $MA_MODULO_RANGE
Safe cams for The modulo range (cam actual value range) for rotary axes with cam can be set
endlessly turning using the following machine data:
rotary axes (840D,
MD 36902/1302: $MA_/$MD_SAFE_IS_ROT_AX
SW4.2 and higher)
MD 36905/1305: $MA_/$MD_SAFE_MODULO_RANGE
The size of the cam actual value range should be selected to match the modulo
display of the safe actual value.
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
SGA = 1
SGA = 0
Hysteresis of cam SGAs
Note
Dynamic deviations in the cam signals at I/O devices themselves still occur as
a result of the different signal run times between the NCK and PLC I/O
devices. These deviations must be taken into account.
MD 36988: $MA_SAFE_CAM_PLUS_OUTPUT[n]
MD 36989: $MA_SAFE_CAM_MINUS_OUTPUT[n]
3 Safety-Related Functions
Cam position
Tolerance
for safe
cams
s
SN_05.DSF
3-117