CanOpen protocol
Positioning module IMD20, IMD40
Syn
Ind
chronous control
ex Sub Name
Type
Attrib Map Default
value
Meaning
2043
Synchronous
control
RECORD
Control of the gantry axis
.
2043
00
Number of entries
Unsigned 8
CONST
N
3
Number of entries.
204
2
Æ
Master axis
3
01
Synchronous mode
Unsigned 8
RW
N
0
0
Æ
No gantry axis
1
Æ
Slave axis
204
02 Slave minimal node
ID
Unsigned 8
RW
N
127
Minimum CAN ID no. of
the slave axis.
3
204
aximal node
Unsigned 8
RW
N
Maximum CAN ID no. of
e slave axis.
3 03 Slave m
ID
127
th
204
N
Fault-free slave
y slave
3
04
Slave error
Unsigned 8
RW
0
0
Æ
1
Æ
Fault
2043
ord
Unsigned 16
RW
Y
0x0027
Master axis status word.
05
Master status w
204
current
Signed 32
RW
Y
on of the
3 06 Master:
position
0
Current positi
master axis.
204
error
Unsigned 32
RW
N
Position window for the
ntry
3 07 Following
window
10000
monitoring of the ga
axis.
204
Signed 32
RO
Y
of
position between the
master and the slave axis.
3
08
Following error
0
Current deviation
2043
09
Help variable
signed 32
RW
N
0
Help variable for the
synchronisation process.
2043
0A
Max. following error
signed 32
RW
N
0
Max. deviation of position
between master and
slave.
2043
0B
Coupling factor
unsigned 8
RW
N
4
Coupling factor with
master axis.
2043 0C Homing Follow Error
Check (Dummy)
Unsigned 8
RW
N
1
Homing Follow Error
Check (Dummy)
With the help of the synchronous control objects given above, the ISEL CNC control realises the operation
of the gantry axis. The “Synchronous Mode” object is set during the CNC operation by the control, if
applicable. Currently, up to 2 gantry axes are allowed per machine. The CAN node ID of the slave axes
are stored in the “Slave minimal node ID” and “Slave maximal node ID” for the monitoring of errors. The
“Slave Error” object is only used by one master axis. If the related slave axis is faulty, this object is set in
the master. In a slave axis, this object is of no importance. During the gantry, the slave axis receives the
status as well as the current position of the master axis in the objects “Master: status word” und “Master:
current position”. By means of these two objects, the slave axis recognises, if the master axis is faulty or
not and if the deviation of position between the master and the slave exceeds the limit value in the
“Following error window” object or not. The current value of the deviation of position between the master
and slave can be seen in the “Following error” object. The “Help variable” sub-index is intended for
internal use only. The “Max. following error” sub-index of the slave axis is an auxiliary means for the
commissioning. The user can launch the ACSetup in the declaration mode and this variable indicates the
maximum deviation of position between the master and the slave. The seven objects mentioned last are
used only by one slave axis. In the master operation, they are not taken into account.
With the exception of the two objects “Following error window” and “Coupling factor”, all objects of the
synchronous control are commissioned during operation by the ISEL CNC control. In the “Can
Interpolation” dialogue box of the slave axis, the position error of a gantry axis can be defined as a value
for the “Following error window” object and the coupling factor of the slave as the value of the “Coupling
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