APPENDIX

Appendix 2.2.2 Installing on existing systems

MELSEC-Q

The following explains the Installation of the Q series C24 on an existing system.

(1) Installing on a multidrop connection system

The Q series C24 can be installed on an existing system to which the PLC CPU and external devices are connected as 1:n or m:n multidrop connection (1). 1 This is when a QC24(N) or a computer link module (such as AJ71UC24) is

used as the PLC CPU module of the multidrop connection.

However, there are frame restrictions when data communication is performed. (See the Reference Manual.)

(2) Replacing the QnACPU module with a QCPU

The wiring used by the QC24(N) can be used as is.

POINT

The functional use is the same, except for the functions added by the Q series C24 to the conventional module. However, with the introduction of high-speed QCPUs, there may be cases in which communication cannot be performed normally when a PLC module in the QnA series is replaced by a Q series PLC. When a module is changed to a Q series PLC module, make sure to perform an operation check.

App. - 9

App. - 9