Description Of Machine Data - Siemens SINUMERIK 840D sl Function Manual

Data Description
8.1 Machine data for SINUMERIK 840D sl
8.1.2

Description of machine data

General information
General information about machine data and an explanation of their contents such
as units, data type, protective stage, effectiveness, etc. can be found in the follow-
ing references:
References:
10090
MD number
Default value: 3
Change becomes effective after: POWER ON
Data type: DWORD
Significance:
Special cases, errors,...
corresponds with..
8-266
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
/LIS/, Lists, SINUMERIK 840D/840D sl
$MN_SAFETY_SYSCLOCK_TIME_RA TIO
Factor for the monitoring clock cycle
Min. input limit: 1
Protection level: 7/1
Ratio between the monitoring and system basic clock cycle. The monitoring clock cycle is
the product of this data and $MN_SYSCLOCK_CYCLE_TIME.
The monitoring clock cycle is checked during run–up:
S
It must be an integral multiple of the position control clock cycle
S
It must be < 25 ms
If these conditions are not fulfilled, the factor is rounded–off to the next possible value. The
monitoring cycle that is actually set is displayed using
$MN_INFO_SAFETY_CYCLE_TIME.
Further, the value for the crosswise data comparison clock cycle that is displayed using
$MN_INFO_CROSSCHECK_CYCLE_TIME also changes.
Note:
The monitoring clock cycle defines the response time of the monitoring functions. It should
be noted that a short monitoring clock cycle time increases the load on the CPU.
MD 10050: $MN_SYSCLOCK_CYCLE_TIME
MD 10091: $MN_INFO_SAFETY_CYCLE_TIME
MD 10092: $MN_INFO_CROSSCHECK_CYCLE_TIME
Max. input limit: 50
Unit: –
© Siemens AG 2008 All Rights Reserved
05.08