The bi-directional feature enables use of these devices in monitoring and control applications and eliminates cable and conduit for analog and digital signals in harsh industrial environments. The RAD-ISM-900-XD-BUS uses spread-spectrum frequency hopping techniques for a license-free, interference-free link between remote devices and control room. Typical in-plant range is 600 to 1,000 feet with no line of sight, and much farther with outdoor applications, says the vendor. The transceivers are powered separately with a 12-30VDC source. Both transceivers and I/O modules are featured in a slim 22.5mm DIN-rail mount housing with integrated bus connection for communications and power.