Model WDRXL-24-420MA, from Imagine Instruments, has been specifically designed to be a wireless bridge between sensors and process instrumentation and controls.
This Wireless Analog Transmitter/Receiver System allows for remotely monitoring sensors or controlling process equipment from a distance up to 1 mile (LOS) line-of-site away using license free wireless 2.4GHz 802.15.4 communication. 
The DIN-rail mounted Transmitter/receiver set is powered by 12-24V DC and provides one 4-20mA analog signal input and output. When a 4-20mA input signal is connected to the transmitter the measurement is sent to the receiver via wireless communication. The measured analog current value is then recreated by the receiver which produces a matching current output. Both the transmitter and receiver are also equipped with one contact closure input that is used to control an open-collector output on the opposing unit for additional control or alarm functionality.
For more information, visit Imagine Instruments website.
