User`s manual

16
CHAPTER2 CC-Link Unit
2-6 Sequencer (master station) settings
The master station sequencer (or PLC) in the CC-Link system can make line tests on the
remote station. Use this function to check whether or not the controller is identified as a
remote station on the CC-Link system before starting any actual work. Refer to the in-
struction manual for the master station sequencer (PLC) for detailed information.
!
CAUTION
When the program is stopped on the master side, an interlock stop may occur in
the controller. If this happens, movement commands cannot be executed.
2-6-1 Starting data exchange with the controller
To correctly transmit and receive data between the master station sequencer (PLC) and
the controller, input the following sequencer (PLC) program from the master station
sequencer (PLC) so the following handshake process will be performed.
If this handshake processing is not performed, and RX(n+3)B is not set to ON, automatic
operation is disabled because emergency stop is triggered.
Perform this handshake process before trying to actually transmit or receive data.
RX(n+3)8
RY(n+3)8
RX(n+3)B
RX(n+3)8 : Initial data request flag
RY(n+3)8 : Initial data end flag
RX(n+3)B : Remote READY
(1) When the controller starts up or when communication with the master station is
disabled because an error occurs in the CC-Link system, the controller turns RX(n+3)8
ON, and turns RX(n+3)B OFF.
(2) Check that RX(n+3)8 is set to ON, and then set RY(n+3)8 to ON from the master
station sequencer (PLC).
(3) After checking that RX(n+3)8 is set to ON, the controller turns RX(n+3)8 OFF, and
turns RX(n+3)B ON.
(4) Check that RX(n+3)8 is set to OFF, and then set RY(n+3)8 to OFF from the master
station sequencer (PLC). The actual data can now be sent and received.