LS Electric PLCs - Communications & Networking

Today's PLCs need to communicate to numerous industrial devices including remote I/O, motor drives, servo controllers, operator interfaces, and oftentimes server-level PCs running various manufacturing related applications. These devices can all use different connection strategies and different communication protocols. Therefore, it's vital for machine builders and other users to install PLCs that can seamlessly connect with existing older networks as well as new ones, since each installation site can have very different communication needs.

• Serial communication, most commonly Modbus RTU, has been around for decades and is still in widespread use. Although reliable, performance is limited and serial protocols are a poor choice for high-speed and other demanding applications.
• Due to faster transmission speeds and other advantages, Ethernet has emerged as the dominant standard for PLC communication and encompasses many industrial protocols such as EtherNet/IP, Ethernet TCP/IP, Modbus TCP/IP, and Profinet. With Ethernet, PLC communication remains fast while talking to several dissimilar devices such as PLCs, HMIs, and field I/O all on the same cable.
• USB and wireless communication like Bluetooth are more recent innovations that are making headway into industrial automation.
  

LS Electric XGB PLC CPUs offer several built-in communication ports that support Modbus RTU/ASCII and Modbus TCP/IP protocols. For most applications, the communication provided by the CPU module is sufficient. Additional ports and protocols can be added to the CPU module using communication expansion modules. 

To add EtherNet/IP capability to the XGB PLC, the XBL-EIPT expansion module is required. Two EIPT cards can be utilized in a rack for applications that require network segregation.

• (2) Ethernet 10/100Base-T (RJ45) ports
• Symbolic variable-based communications for easy connections with other PLCs
• Supports encapsulated messages, UCMM explicit messaging, Class 3 connected explicit messaging (server only) and Class 1 connected implicit (I/O) messaging (cyclic I/O service only)
• 16/32 TCP client/server connections
• 32/64 CIP (I/O communication) client/server connections

The XBL-EMTA is an Ethernet expansion module that features one 10/100Base-T (RJ45) port and supports Modbus TCP client/server connections and the XGT protocol. Up to two XBL-EMTA modules can be added to the LS Electric XGB PLC when additional Modbus TCP communication ports are needed.  

If additional serial connections are required, the XBL-C21A is an RS-232 expansion module featuring one RS-232 (DB9 female) port; the XBL-C41A is an RS-485 expansion module with one RS-422/RS-485 (5-pin terminal) port. Both modules support Modbus RTU, Modbus ASCII, and the LS XGT protocol.