Omron CS1W-MCH71 Operation Manual page 370

Command Details
Note
Precautions When Using
Cam Data Continuously
• When these conditions are not met, "CAM (Electronic cam, single axis)"
and "CAMBOX (Electronic cam, synchronous)" commands may cause the
axis to stop operating, or to operate in an unexpected way. To avoid acci-
dents, make sure that the conditions are met.
The position data and global general variable can be used while being over-
written real-time. Therefore, the MC unit does not internally check the condi-
tions for the restrictions mentioned above. (This also applies to the cam data.)
Restriction on the displacement:
Set it so that the value is within the setting range.
The timing may need to be adjusted using the NOPS command when the axis
is continuously moved using the CAMBOX command. The following example
is given as explanation.
As the following program shows, J05 and J04 are connected to the main axis
J02 using the CAMBOX command. If the slave axis J05 is moved immediately
after J02 positioning (completion of line 2), the movement of J05 in line 1 is
cancelled and J05 will be short one unit cycle of reaching the target position.
This happens because when the CAMBOX command in line 3 is executed,
the CAMBOX command in line 1 has not yet completed processing one unit
cycle, thereby cancelling this unit cycle upon the execution of line 3.
CAMBOX [J05]1 [J02]1000 K10000 Q9;
CAMBOX [J04]2 [J02]1000 K10000 Q9;
INC MOVE [J02]1000;
CAMBOX [J05]1 [J02]1000 K10000 Q9;
CAMBOX [J04]2 [J02]1000 K10000 Q9;
INC MOVE [J02]1000;
To deal with this problem, insert a NOPS command after the MOVE command
as shown below. By inserting the NOPS command, the CAMBOX command
will be executed after line 1 is completed.
CAMBOX [J05]1 [J02]1000 K10000 Q9;
CAMBOX [J04]2 [J02]1000 K10000 Q9;
INC MOVE [J02]1000;
NOPS;
CAMBOX [J05]1 [J02]1000 K10000 Q9;
CAMBOX [J04]2 [J02]1000 K10000 Q9;
INC MOVE [J02]1000;
NOPS;
Unit Versions Before Unit Ver. 3.0
If the next operation is executed while the Master axis is continuing to travel,
some of the Slave axis travel distance (up to one Unit cycle of travel) will be
eliminated.
Case First command Next command
1 CAMBOX
2 CAMBOX
3 MOVELINK
4 MOVELINK
←(1)
←(2)
←(3)
CAMBOX Part of the travel distance specified in
the first CAM table will be eliminated
when switching from the first CAM table
to the next CAM table.
MOVELINK As above.
CAMBOX If there is a deceleration area in the first
MOVELINK command, part of the
deceleration area will be eliminated
when switching to the next command.
If there is no deceleration area in the
first MOVELINK command, the axis will
travel the expected travel distance.
MOVELINK As above.
Section 6-3
Remarks
325