New cellular router adds Modbus for M2M data collection

Network World - A new cellular router from Sixnet links monitoring and control networks that rely on the widely used Modbus protocol with centralized servers. Using an emerging class of affordable machine-to-machine data plans, the router creates cost-effective, real-time access to hard-to-reach control data.

Compared to its predecessor, the new IndustrialPro Plus router incorporates a full Modbus gateway that can work as master or slave, peer-to-peer Modbus data transfer between devices, and message forwarding. Also new is a C/C++ software development kit for building programs that can sift the Modbus data and even trigger actions on the monitored equipment.

Sixnet's routers interconnect a range of what are dubbed remote terminal units (which take signals from sensors and meters and convert them into digital data to be passed upstream), and programmable logic controllers, over a cellular link to a central supervisory control and data acquisition (SCADA) system. Modbus is one of the most common protocols used by this class of devices [for more background, see the Modbus Web site]. These systems monitor a vast range of industrial, infrastructure and facilities processes, such as power generation or transmission grids, oil refining, gas pipelines, chemical manufacturing, and heating and air conditioning systems.

But getting the data from remote to central sites in the past required wired connections, sometimes prohibitively expensive or impossible, or periodic data collection visits by employees. But increasingly, wireless carriers are offering cost-effective monthly data plans - ranging from $10 to $50 a month, according to Sixnet - for what are typically low-bandwidth, periodic, machine-to-machine data collections, anywhere from 9K to 100Kbps. Sixnet, based in Ballston Lakes, N.Y., near Albany, is one of a number of companies servicing this market.

Like the previous model, Sixnet's new IndustrialPro Plus router supports 2G, 2.5G, and 3G cellular connections: dual-band CDMA2000 EVDO Rev. A, backward compatible with 1xRTT; and GSM HSPA, backward compatible with EDGE. It includes a 10/100 Ethernet port, with an option for a built-in five-port Ethernet switch; RS-232 serial interface, and one USB 2.0 mini port.

The compact, ruggedized unit - about the size of thick paperback book, just under 5 x 4 inches and just over 1 inch thick (or 2 inches for the four-port Ethernet switch model) - now includes native Modbus support, Modbus gateway, and peer-to-peer Modbus transfers. Security features include IPSec VPN and SSL support, a stateful firewall, packet filtering, access control lists. The router supports NAT, port forwarding, dynamic DNS, and DHCP.

The new unit makes for simpler wireless deployment, and simpler Modbus networking, says Mahesh Patel, Sixnet's director of product management, wireless solutions. The new router can replace separate boxes for device management and for Modbus gateway functions.