Write Timing At Transmission - Renesas R-IN32 Series User Manual

R-IN32 Series CC-Link Remote device station
13.3

Write Timing at Transmission

Completing the processes (1) and (2) described below in a period of time between the rising of a CCS_REFSTB signal
and the rising of a next CCS_REFSTB signal serves to maintain the continuity of the looped back SQ values.
If the continuity of the looped back SQ values is broken, the master station will assess that the slave station has not
correctly received the data and then send data in packets from the beginning again. Therefore, be sure to complete the
processes (1) and (2) within the time between the rising of a CCS_REFSTB signal and the rising of a next CCS_REFSTB
signal.
(1) After confirming the completion of reception processing by the rise of a CCS_REFSTB signal, set the
received SQ from the master station as a loopback SQ and then writes the send data (from [fraction
number – 1] to 0) to the update buffer sequentially. (The CCS_REFSTB signals should rise when
refresh data is received during refresh & single station polling.)
(2) After completing the process (1), check the falling of a CCS_REFSTB signal and then turn ON the
send data write complete (CCS_M3SDOK_RDRQ). (CCS_REFSTB signals should fall after a refresh
cycle has been completed). With the process (2) above, what is stored in the CCS update buffer will
be transferred to the send buffer to be used for transmission and then sent to the master station in the
next polling.
Note: System configuration with the shortest link scan time
・Transmission rate: 10 Mbps
・Slave station: A single remote device station (the number of stations occupied: 1)
(For the system configuration described above, the link scan time is about 1.1 ms).
In summary, the transmission rate of looped back SQ values should satisfy the following three conditions:
・Process (1) + Process (2) ≤ Shortest link scan time (about 1.1 ms)
・Process (1) should take place after the rising of a CCS_REFSTB signal.
・Process (2) should take place after Process (1) has been completed and after the falling of the CCS_REFSTB signal.
R18UZ0056EJ0102
Dec. 28, 2018
13. Notes on Developing with CC-Link Version 2
Page 68 of 83