Hivertec motionCAT HCPCI-MNT720M, User Manual

Page: 160 / 168

149
8.2.9 Data Communication
Data communication is used to send commands to operate motion devices.
Data communication is performed by interrupting the cyclic communication at any time (when a command is sent
from the software).
The following figure shows an example of cyclic communication sequence.
The arrow in the figure represents the sequence in cyclic communication. If a data communication command is
issued at [A], it becomes as follows:
Although the time required for one cyclic communication is extended, the data exchange with the target device
can be performed promptly.
In data communication, as in cyclic communication, a response communication is transmitted to the center device
from the local device that has received data.
Note: Data communication is performed "at any time" as mentioned above, yet within the following constraint:
One cyclic communication must be inserted when performing consecutive data communications or
retrying a data communication due to a communication error.
M ID = n+1 M ID = n M ID = n+2 M ID = m
[A]
M ID = n+1 M ID = n M ID = n+2 M ID = m
Data
communication
A
[B]
M ID = n+1 M ID = n M ID = n+2 M ID = m
[A]
M ID = n+1 M ID = n M ID = n+2
M ID = m
Data
communication
A
Data
Communication
B
M ID = n+3