Chapter 1 Functions; Cyclic Transmission - Mitsubishi Electric MELSEC iQ-R Series User Manual

1
FUNCTIONS
1.1

Cyclic Transmission

This section describes periodic data communications among stations on the network using link devices.
• The link devices can be assigned in "Network Configuration Settings" under "Basic Settings". ( Page 117 "CC-Link IE
TSN Configuration" Window)
• The link refresh is assigned in "Refresh Settings" under "Basic Settings". ( Page 99 Refresh Settings)
Cyclic transmission operates as follows with the communication mode set by the module parameter of the master station.
Communication mode
Unicast mode
Multicast mode
• When cyclic transmission is performed in multicast mode, the local station cannot receive RX and RWr sent
by the CC-Link IE TSN Class A remote station. ( Page 23 Multicast mode)
• To allow the local station to obtain RX and RWr sent by the CC-Link IE TSN Class A remote station, use the
program to send RX and RWr from the master station to the local station. ( Page 133 Communication
Example with CC-Link IE TSN Class A Remote Station)
• In multicast mode, set "Communication Period Setting" for the local station under "Network Configuration
Settings" to "Basic Period".
• If a data link error occurs in multicast mode, ERR LED at the local station flashes. However, even if a data
link error occurs at the CC-Link IE TSN Class A remote station during data link, ERR LED at the local station
does not flash. (The LED remains off.)
• In multicast mode, 'Data link error status of each station' (SB00B0) and 'Total number of slave stations
present value' (SW0059) at the local station can be checked by SB and SW. However, the information on
the CC-Link IE TSN Class A remote station may not be checked by some SB and SW.
1 FUNCTIONS
18
1.1 Cyclic Transmission
Description
• Cyclic data is sent to one station.
• When this communication mode is used, the local station cannot receive cyclic data from another station. Use this mode
when there is no local station or when it is not required for the local station to receive cyclic data from another station.
• The cyclic transmission time of this mode is shorter than the cyclic transmission time of multicast mode. ( Page 293
Communication cycle intervals)
• Cyclic data is sent to multiple stations.
• When this mode is used, the local station can receive cyclic data from another station. Use this mode when it is required for
the local station to receive cyclic data from another station.
• The cyclic transmission time of this mode is longer than the cyclic transmission time of unicast mode. ( Page 293
Communication cycle intervals)