Group Number Setting - Mitsubishi Electric MELSEC iQ-R C R12CCPU-V User Manual

Group number setting

This function divides slave stations into groups by setting a group number to each slave station and each of groups performs
cyclic transmission.
By organizing groups separating slave stations with shorter response processing time from ones with longer response
processing time, the differences of the reference response times of each slave station does not affect the cyclic transmission.
(1)
(2)
(1) Group No.1
(2) Group No.2
• The total number of occupied stations for one group is 16 maximum.
• Slave stations can be divided into up to four groups.
How to organize groups
Organize groups considering the following.
■Dividing slave stations into groups
• Organizing two or more groups can configure a network with slave stations that occupy 17 or more stations in total.
• By dividing slave stations into groups with similar reference response time, the gap of the response time of each slave
station does not badly affect the cyclic transmission. For details on the reference response time, refer to the manuals for
slave stations used. Link scan times vary from group to group. The link scan time of each group is affected by a slave
station that has the longest reference response time in a group. (Page 127 Data transitions of cyclic transmission)
■Merging slave stations into one group
• To perform operation among slave stations in cooperation, merge them into the same group.
• When the line load is large, merging slave stations into the fewest number of groups as possible according to the number of
slave stations connected to the master station is recommended. For example, merge slave stations into one group if the
slave stations are 16 or less. When two or more groups are organized, the master station sends requests to each of them.
Since the packets of the cyclic transmissions performed for each group are sent on the line, the more groups are organized,
the larger the line load becomes.
7 CC-Link IE Field Network Basic FUNCTION
132
7.1 Cyclic Transmission Function