Mitsubishi MELSEC-A Series Reference Manual page 88

5. SPECIFICATIONS
(b) Three-tier system configuration
1) In the configuration of the three-tier system, the link parameters are set in the
master station for the second tier and the master station for the third tier.
2) The master station and local stations for the second tier (including the master
station for the third tier) can read the range assigned by the link parameters
of the master station for the second tier.
3) The local stations for the third tier can read the entire range assigned by the
link parameters of the master station for the third tier and the range assigned
to host station (the master station for the second tier) by the link parameters
of the master station for the second tier.
The range assigned to the local stations for the second tier and the range
assigned by link parameters of the master station for other third tier cannot be
read.
The read/write range of each station is explained by showing Fig 5.2 as an
example.
Fig 5.2 Three-Tier system configuration
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