4.1 Operation of PLC Link MEWNET-W04.1.1 Operation Overview of PLC Link● “Link relays (L)” and data registers “link registers (LD)” are shared between connected PLCs.● In the case of link relays, if the link relay contact of one PLC turns ON, the same link relaysalso turn ON in all PLCs on the same network.● Likewise, in the case of link registers, if the content of a link register in one PLC is rewritten,the value of the same link register is changed in all PLCs on the same network.PLC PLC PLC PLCRS-485No.1 No.1 No.1No.2 No.2No.3No.3No.3No.2(Unit No. 1) (Unit No. 2) (Unit No. 3) (Unit No. 4)Send areaSend areaSend areaReceive areaReceive areaReceive areaReceive areaReceive area4.1.2 Roles of Link Relays and Link Registers■ Link relayIf link relay L0 in the master unit (No.1) is turned ON, the state change is fed back to link relayL0 that has the same number in other units, and R0 is outputted from these units.4.1 Operation of PLC Link MEWNET-W04-2 WUME-FP0HCOM-06