Mitsubishi MELSEC-A Series Reference Manual page 53

4. COMPOSITION OF A THREE-TIER SYSTEM
(3)
(b) For the CPU module any of the AnUCPU, A2ASCPU(S1), A2US(H)CPU(S1),
QnACPU, and Q2AS(H)CPU(S1)
Up to two of the following link modules (one as a master station and the other as
a local station) can be used with a CPU module.
(The two modules cannot be used only for master stations or local stations.)
AJ71AP21
AJ71AP21-S3
A1SJ71AP21
AJ71AR21
A1SJ71AR21
When using a CPU module with link function as a master station for the third tier
In a three-tier system including a CPU module with link function and a data link
module, the CPU module can be used as a master station for the third tier and the
data link module as a local station in the second tier.
Note that the following AnACPUP21/R21 versions and later can be used as a master
station for the third tier.
When configuring a three-tier system with a version earlier than that, use the
AnACPUP21/R2 as a local station in the second tier, and a data link module as a
master station for the third tier.
CPU module with link function
A2ACPUP21
A2ACPUR21
A2ACPUP21-S1
A2ACPUR21-S1
A3ACPUP21
A3ACPUR21
4 - 5
Version
107CX
107BX
107BY
107BY
107CZ
107BZ