If an input is used in a task and this task is then interrupted by a higher-priori‐
ty task using the same input, the process image at this point of time is upda‐
ted for the high-priority task. The low-priority task then continues to run and
reads the possibly new value. This should be taken into account when sever‐
al tasks of different priority are used.
Writing to the same outputs in a variety of tasks should be avoi‐
ded!
Start Values
The value of the start values depends on the declaration of the variables:
●
Without pre-initialization all variables are set to "0".
●
With pre-initialization all variables are preset to the corresponding initial‐
ization value. Example: "MyOutput AT %QX2.4 : BOOL := TRUE;"
Safe Values in "STOP"
In the "STOP", "RESET" or, if applicable, "Watchdog" states, all outputs are
"0", the output variables in the process image of the outputs remain un‐
changed.
Safe Values in Case Connection is
Interrupted
●
In case the connection to the master control unit is interrupted, the as‐
signed inputs are set to zero.
●
In case the connection to the slave axes is interrupted, the assigned in‐
puts are set to zero.
●
In case the connection to the sercos III I/O devices is interrupted, the
assigned inputs are set to zero.
Processing Digital Values
When digital values are processed, it is also possible to use individual bits in‐
stead of whole Boolean variables; however, this has an unfavorable effect on
the processing rate.
Bit-by-bit processing is possible with all digital inputs/outputs, byte-by-byte
processing is only possible with the digital inputs/outputs on the control sec‐
tion and the parallel interface.
Multitasking
If access is made to bits which belong to a byte, it is possible to safely access
individual bits in spite of preemptive multitasking (read - modify - write).
Setting and clearing of bits by the PLC cannot be interrupted and
therefore are "task-proof"! This however does not apply to exter‐
nal access (e.g., via the programming system)!
"AxisData" cyclic axis data
Brief description
There are predefined axis data structures ("AxisData") with several command
values and actual values available for cyclic access to the local axis and re‐
mote axes.
Features
●
"AxisData" is an IEC61131 data structure definition which contains
some important actual values of the axis. In addition, it contains configu‐
rable actual values and command values with which the user can read
and, if necessary, write their own cyclic data. This allows easy access to
the most important axis data.
●
The "AxisData" structure is already declared as an "Array of Struct" ar‐
ray across all real axes in the "MX_Base" library.
AxisData : AR-
RAY[1..10] OF MX_AXISDATA
.
Activating "AxisData"
Processing the "AxisData" structure is optional, so it requires activation. The
"AxisData" structure is activated by the PLC configuration P-0-1367, bit6=1;
by default; the "AxisData" structure is not active.
DOK-INDRV*-MLD3-**VRS*-AP02-EN-P
Bosch Rexroth AG
91/267
Rexroth IndraDrive Rexroth IndraMotion MLD (2G) as of MPx-18
MLD communication interfaces and data channels
LSA Control S.L. www.lsa-control.com [email protected] (+34) 960 62 43 01