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It is possible to connect it by specifying IP address of reading another station via past MELSECNET but the object station though various communication interfaces are supported in GX Developer. If this is used well, two or more PLC in LAN can be managed, and be operated remotely with one PC.
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Commentor / R.Takeuchi |
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Maintained with PLC in the factory together by using Ethernet! |
Ladder development software "GX Developer" can be accessed to PLC by using a variety of communication media with usual Ethernet and CC-Link besides communicate by using a usual CPU port.
In the connection that used a usual CPU port, when it tried to edit the program of a different PLC, had to move to the control board and to exchange the cable.
Only, though there was a method of accessing another station that used the transient transmission function of MELSECNET assuming that it seemed to be network management. MELSECNET2 was only able to access the parent station and it took unexpected much time to be read "parameter + main".
To maintain "Ladder", it is improved by using various interface such as CC-Link, Serial, and Ethernet to use GX Developer.
When it becomes a large factory, especially IPX and TCP is Ethernet is considerably attractive that achieve a high speed communication of 100Mbps. Because LAN is equipped at most of factory, it needs to cost of the cable is constructed. If Ethernet is used, all PLC in LAN is possible to flat connection.
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This is a screen of "the connection destination" of GX Developer, When Ethernet is connected though the shade of meaning "IP address on PC side is No**, and PLC side is No**" is set.
To be careful, is to need to setup "Network Number" of the Ethernet unit to the parameter of PLC.
In "Network Number", a usual socket communication has nothing to do with Ethernet. Though is a virtual number of original MELSEC, with the using this, it can access PLC that exists in another hierarchy. This is a convenient point.
Access PLC like this can specify by IP address (accurately IP address and Network No / Station No). And if it is a PLC in LAN, easily is possible to connect of it.
For example, the controller in the factory can be done to be managed in block at operation room, and to be changed in CPU running. Moreover, if an overseas factory are connected internet, you need not to visit an overseas factory and are possible to do the first maintenance.
Actually, as there is often a case to need often visual check on safety, though remote change are few, without visiting on the site of factory and you want to monitor the insider information of PLC, don't you.
Moreover, if you think about the maintenance of the factory where not only MELSEC but also PLC of various makers' named SYSMAC and FA-M3 coexisted together and to bring "the cable for MELSEC" and "the cable for SYSMAC" into the factory, and you exchanges of the cables and accesses. we think, it is very inefficiency. Have only to have a LAN cable, and you can maintain the variously of PLC maker. We think that this is a figure of reasonable Factory Automation.
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Inside MELSEC
Advanced OPC