Wireless I/O accepts 4-20 mA, two digital signals

To eliminate cables between serial nodes and point-to-multipoint networks, Phoenix Contact and Omnex Control Systems recently developed and released their RAD-Data Series (DS). RAD-Data evolved after Phoenix used Omnex's Trusted wireless I/O and data radios to develop its Measurement Control Regulation-Radio Analog Digital (MCR-RAD) technology, which transmits small packets, usually 16-18 bits ...

By Staff January 1, 2005

To eliminate cables between serial nodes and point-to-multipoint networks, Phoenix Contact and Omnex Control Systems recently developed and released their RAD-Data Series (DS). RAD-Data evolved after Phoenix used Omnex’s Trusted wireless I/O and data radios to develop its Measurement Control Regulation-Radio Analog Digital (MCR-RAD) technology, which transmits small packets, usually 16-18 bits at 96 kbps and at relatively high power, up to the 1-watt maximum allowed by federal regulations. This allows MCR-RAD’s signals to penetrate objects better and transmit over longer distances. The partners’ first product was RAD-UD (uni-directional), which accepts one signal. In response to user requests, they next produced RAD-BD (bi-directional), which accepts multiple I/O signals, up to 33 analog or 66 digital or a combination.

“Process applications are always measuring and transmitting temperature, pressure, level, and flow, usually with 4-20 mA analog signals that indicate status, or with digital alarm signals,” says Davis Mathews, Phoenix’s instrumentation and wireless marketing manager. “So, we and Omnex came up with a device that would wirelessly accept one 4-20 mA signal or two digital inputs, but one that required no set up or programming.”

As a result, users will be able to put a RAD-Data Bus at each station, and connect I/O points directly to them, which will eliminate the need for a PLC at each station in applications where the PLC is usually surrounded by multiple I/O points. “This will allow users to make their controller the master in a Modbus network,” adds Mathews. “Meanwhile, the stations will automatically become slaves in this network because they will look like PLCs to the master controller. Once this is done, Modbus will register analog and discrete signals like it would in a normal, wired PLC network. This is basically a wireless way to do some traditional networking, but it’s possible without having to change what’s already been done.” www.phoenixcon.com or www.omnexcontrols.com

Point-to-multipoint wireless I/O & data

Eliminates need for remote PLCs

Read and write analog/digital registers via Modbus or AB DF1

High-density, expandable I/O