The NC cycle time is specified by the higher-level master commu‐
nication master only if the sercos III master communications is
used. For all other master communications, the NC cycle time can
be freely set via parameter "S-0-0001, NC cycle time (TNcyc)".
Consider the following aspects when setting the NC cycle time in conjunction
with the motion task in synchronism with master communication:
●
The minimum allowed NC cycle time is 1 ms. All integral multiples of the
minimum allowed NC cycle time are also allowed.
Application
The time MLD-S is called should be synchronized for physically separate
drives so that each MLD-S can react to command values and actual values at
the same time. For this purpose, the task is synchronized with the NC cycle.
Example
A higher-level control unit cyclically writes master axis positions to a global
PLC register. MLD evaluates the master axis positions and adds a master ax‐
is offset to them. The result is written to parameter "P-0-0053, Master axis
position". When the next MDT (Master Data Telegram) is received, the drive
applies the value of P-0-0053. This means the command value from the NC
is subject to an offset and takes effect one NC cycle later.
Timing
With MLD, the motion task in synchronism with master communication starts
after and ends before the MDT and AT are processed (MDT: Master Data
Telegram; AT: Antriebs-Telegramm [drive telegram]).
Motion task in synchronism with CCD
The motion task in synchronism with CCD is a task synchronized with the
CCD cycle (MS channel).
It is created by an "external event" task with the system event
"CCD_SYNCHRONIZED_TASK".
If the axis is a CCD master axis and CCD is active, the motion
task in synchronism with CCD is only allowed in the MLD-M sys‐
tem mode.
If CCD is not active or the axis is not a CCD master axis, a motion
task in synchronism with CCD configured in the PLC project is
handled like a motion task in synchronism with master communi‐
cation. In this case, the description of the motion task in syn‐
chronism with master communication applies.
Motion task cycle time (CCD cycle
time)
If sercos III master communication is used, the CCD cycle time (and with it
the motion task cycle time) corresponds to the "producer cycle time"
(S-0-1050.x.10) of the connection configured by the master in the MDT, if this
time is shorter than the value of "P-0-1800.0.10, CCD: Cycle time". With all
other master communications, the motion task cycle time, as well as the CCD
cycle time, correspond to the NC cycle time [S-0-0001, NC cycle time
(TNcyc)], provided the NC cycle time is shorter than the value of
"P-0-1800.0.10, CCD: Cycle time". If not, they correspond to the value of
"P-0-1800.0.10, CCD: Cycle time". The active CCD cycle time can be taken
from parameter "P-0-1810.0.0.3, CCD: Timing settings".
Consider the following aspects when setting the CCD cycle time in conjunc‐
tion with the motion task in synchronism with CCD:
●
The minimum allowed CCD cycle time is 1 ms. All integral multiples of
the minimum allowed CCD cycle time are also allowed for the motion
task in synchronism with CCD.
Bosch Rexroth AG
DOK-INDRV*-MLD3-**VRS*-AP02-EN-P
62/267
Rexroth IndraDrive Rexroth IndraMotion MLD (2G) as of MPx-18
Basic functions of Rexroth IndraMotion MLD
LSA Control S.L. www.lsa-control.com [email protected] (+34) 960 62 43 01