Example: Measuring System Switchover When Encoders Are Missing In Certain Parts Of The Range - Siemens SINUMERIK 840D sl Function Manual

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3.2.9.5 Example: Measuring system switchover when encoders are missing in certain parts of
the range
In the following example, the direct linear position measuring system is only available in the
machining zones, while only the motor measuring system is available outside the machining
zones.
Initial situation
● Linear axis "X" has two incremental encoders:
– Motor encoder E1
– Direct linear encoder E2
● Direct linear encoder E2 is only available in the machining range.
● One of the following two telegram types is configured in MD13060
$MN_DRIVE_TELEGRAM_TYPE (standard telegram type for PROFIdrive):
– Telegram 116 (motor encoder + an external encoder)
– Telegram 136 (motor encoder + an external encoder, and torque precontrol)
● The following position measuring systems are configured for the machine axis:
– Motor encoder E1 as position measuring system 1
– Direct linear encoder E2 as position measuring system 2
● When the machine is switched on, the user activates both position measuring systems:
– DB31, ... DBX1.5 (position measuring system 1) = 1
– DB31, ... DBX1.6 (position measuring system 2) = 1
When both position measuring systems are simultaneously activated, then the control
selects position measuring system 1 as active position measuring system.
● Position measuring system 2 is selected for machining:
– DB31, ... DBX1.5 (position measuring system 1) = 0
– DB31, ... DBX1.6 (position measuring system 2) = 1
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Attachment head "A" is now mounted on the spindle.
The user activates position measuring system 2:
DB31, ... DBX1.6 (position measuring system 2) = 1
As a consequence, position measuring system 1 is also simultaneously activated; This
is because the "Park passive position measuring system" function is not active for po‐
sition measuring system 1. Position measuring system 1 becomes a passive position
measuring system.
The controller then sets the status signals for the position measuring systems:
DB31, ... DBX102.5 (position measuring system 1 activated) == 1
DB31, ... DBX102.6 (position measuring system 2 activated) == 1
or
A3: Axis Monitoring, Protection Zones
3.2 Axis monitoring functions
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