Specifications

3-8
3.3 Functions
3.3.1 Function block diagram
How I/O data are transferred to/from the servo amplifier in CC-Link will be described
using function blocks.
(1) Between the master station and servo amplifier in the CC-Link system, link refresh is
always made at 3.5 to 18ms (512 points). The link scan time for link refresh changes
depending on the communication speed. For details, refer to the CC-Link System
Master/Local Unit User's Manual.
(2) I/O refresh and master station's sequence program are executed asynchronously. Some
PLCs can synchronize the link scan with the sequence scan.
(3) Data read from the servo amplifier are read from the buffer memory of the CC-Link
system master/local unit using the FROM instruction, and data are written using the
TO instruction. Some PLCs allow the FROM/TO instructions to be omitted by setting
automatic refresh.
1) AJ61BT11
I/O signals
CPU
Buffer
memory
2) Buffer memory read/write
3) Twisted pair
cable
(3-wire type)
Input
Output
Servo amplifier
PLC CC-Link unit
PLC CPU
Interface with PLC
CC-Link interface CC-Link interface
I/O interface
Servo amplifier CPU
3.3.2 Functions
The
following table indicates the functions that can be performed from the PLC in a
CC-Link
system while the
CC-Link
or test operation mode is selected.
Operation Modes
Item
CC-Link operation mode
Servo configuration software
test operation mode
Monitor
Operation
Parameter write
Parameter read
Point table write
Point table read