Wireless system combines speed and security

Frequency hopping and multiple slave units provide safe, reliable communication

By Control Design Staff

The EX600-W series wireless system is designed to provide safe and reliable communication, using the 2.4-GHz radio frequency bands reserved for industrial, scientific and medical (ISM) use.

It provides stable communications using various forms of radio-wave propagation, including direct wave, transmitted wave and reflected wave, with communication between master and slave possible in a 10-m (33-ft) radius.

The system has a signal response time of 5 ms, as well as a high-speed connection of 250 ms for a wireless slave from power on.

It can accommodate a maximum of 1,280 inputs/1,280 outputs; registration and communication of as many as 127 slave units is possible. One to 15 units are recommended for simultaneous operation, and it is possible to install multiple wireless masters in the same area.

“The EX600-W wireless system means reduced wiring work, space and cost,” says Andy Thedjoprasetyono, head of project management at SMC. “Disconnection risk is minimized. And 5-ms frequency hopping guarantees a stable wireless environment is established using an original protocol that’s not affected by interference. Interference from other wireless equipment is prevented.”

The EX600-W was originally created for the automotive industry, where use of robotics for welding and assembly are common. “Since the release we have found that the machine-tool industry, food and packaging and electronic equipment manufacturers have applications that can utilize the wireless feature of EX600-W,” says Thedjoprasetyono.

“Industrial applications that would benefit from the wireless EX600 include welding lines, assembly or conveyor lines using rotating jigs, industrial applications using slip rings, tool changers and any equipment where wiring is difficult or with scattered I/O at multiple locations,” explains Thedjoprasetyono.

The communication technology rapidly changes frequency to prevent interference from other wireless equipment. When the frequency of Wi-Fi and other wireless communications compete, or radio wave interference is present, then other frequencies are used for communication.

Unauthorized access from outside is prevented by using data encryption.

Wireless communication status also can be monitored during operation according to the diagnostic data, such as when communication from the slave can’t be received or when communication retry has exceeded the upper limit of 32 times.

The installation location can be ascertained according to the intensity level of the radio wave received by the unit display. A received radio-wave intensity level of 1 means the intensity is weak. Add a wireless master so that the wave intensity becomes level 2 or 3.

Alternatively, remove the obstacle between the master and slave, or you can reduce the distance between the master and slave.

White paper download: Wireless Connectivity for the Internet of Things

Communication status also can be downloaded by a PC. By connecting the wireless master to a PC, it is possible to view log files that show the number of retries or the received radio-wave intensity. Log files are accessed by using a Web browser to connect to the built-in Web server.

The wireless environment and installation location can be optimized by checking the number of retries and received radio-wave intensity. The log files, showing the number of retries or the received radio-wave intensity, can be downloaded in the form of a CSV file.

Settings are possible using a near field communication (NFC) reader/writer and setting software. Some items can be set when there is no power supplied. Using a PC and NFC reader/writer, you can:

• write IP address to the master

• set the I/O points for the system and unit

• pair the master and slave

• monitor I/O.

The wireless system comprises wireless master unit for EtherNet/IP and wireless slave units.

Slave options include digital input units, digital output units, digital input/output units, analog input units, analog output units, analog input/output units, D-side end plate and U-side end plate.

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