Phoenix Contact, Middletown, PA, has added the Modbus TCP/UDP and Modbus RTU/ASCII bus couplers and a backplane expansion module to its Inline Modular family of I/O products. The 80 mm wide Modbus TCP/UDP bus coupler incorporates 8 digital inputs, 4 digital outputs, and a built-in Ethernet switch and uses BootP to assign IP addresses. The Modbus RTU/ASCII bus coupler includes 8 digital inputs, 4 digital outputs, an incorporated power terminal, and an RS-485 D-SUB connection for Modbus. The backplane expansion module has a max. capacity of 63 devices and lets you expand the local bus onto a second rail within the control cabinet.