Wireless RS-485 Communication between Controllers and the Kontar MC8W

It isn’t always practical or cost-effective to pull wires. In fact, sometimes it is simply impossible. This is where RF (Radio Frequency) modems come into play. Arecont’s Kontar™ controllers are tested and certified for use with Aerocomm ConnexLink™ CL4424-100 RF Transducers for point to multipoint configuration.

Aerocomm's Transducers (PDF)

These transducers work in the license-free 2.4GHz frequency range and provide a simple, cost-effective solution to many wiring problems. When properly connected, they seamlessly transmit the Kontar communications data between controllers at the same data rate as the wired RS-485 network. The CL4424-100 Transducers work with Kontar MC8W controllers. An MC8W controller is basically a standard MC8 controller with a modified operating system. So it’s possible to have an existing MC8 controller modified (upgrade charge applies), but it must be sent back to the manufacturer for the wireless upgrade. An MC8W controller is capable of both wired and wireless communication.

Powering CL4424-100 RF Modems

There are two ways of powering the modems:
1. Using provided with the modem wall power supply, plugged into power connector on the modem.
2. Using any power supply, providing from 6 to 18 VDC with current not less then 125 mA. In this case plus must be connected to terminal 1 of screw type terminal block and minus to terminal 6.

Connecting CL4424-100 RF Modem to the Controller

Pin Description

1 - VCC (6 –18V, 125 mA max)
2 - 485- (485B) Connect to terminal 28 of the MC8W
3 - No Connect
4 - No Connect
5 - 485+ (485A) Connect to terminal 27 of the MC8W
6 - GND

Modems purchased from Arecont come preconfigured. The “server modem” (in Aerocomm terminology), must be connected to the MC8W master controller. Modems configured as “clients” must be connected to the slave controllers. All client modems are identical.

Antenna Connection

The modems come with a half-wave, dipole antenna. Modems with these antennas provide an average range of 500 feet indoors and one mile outdoors (line-of-site). Using high gain directional antennas can significantly increase the distance.