Remote terminal units are part of Supervisory Control and Data Acquisition (SCADA) systems. A remote terminal unit for SCADA systems controls and measures settings like speed, depth, energy consumption, temperature and other variables. If an event occurs that causes conditions to reach a predetermined level, remote terminal units send alarms and messages to phones and beepers.

A remote terminal unit (RTU) is usually used in industrial settings, such as factories, plants, wells, pipelines and tanks to control functions like speed of a conveyor belt or depth of liquid in a tank. They can also be used to report alarms in office security and network equipment. A remote terminal unit is the most important part of your network monitoring, so it must:

1. Use RTU communication protocols that fit your organization's needs;

2. Provide accurate control and measurements;

3. Be rugged and able to handle varying temperatures and tough environmental conditions.

Action Steps
The best contacts and resources to help you get it done

Get remote terminal hardware that works in your setting

Find an RTU that is right for your industry and size.

I recommend: The Barton CryoScanCS51 Telemetry System measures pressure and levels in a tank and submits data over a cellular line or land line. The Opto 22 RTU Modular Controller from Davis Inotek Instruments LLC is used to monitor tank farms, wells, pipelines and remote plants. It can be used as a stand alone device or as a gateway to other control devices. The GE Power Leader ModBus Monitor connects to ModBus RTU networks and reads metering and status information collected by Power Leader power management devices. It offers centralized data viewing from remote devices. Remote terminal units from Comtech M2M Limited are suitable for small sites. The unit can be monitored over the Internet, eliminating the need for computers or software at the site. It measures energy consumption, temperature and other equipment variables.

Buy remote terminal units that monitor office equipment

Get a simple system that reports alarms on a network or security system.

I recommend: The Mironix Eagle is a compact device that reports alarms and events through software or a central SCADA System. Units from DPS Telecom use dialup or local area networks to report alarms.

Get a wireless remote terminal unit

For your next upgrade, consider a new generation wireless RTU.

I recommend: The ScadaBridge Wireless RTU transmits over broad spectrum radio. It can serve as a slave in a radio-based SCADA system or as a bridge between remote locations. VMonitor.com offers units that are battery operated and uses multi-frequency spread spectrum communications. They work in harsh environments and wide temperature ranges.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  When selecting a remote terminal unit, take an inventory of your current systems. Look for an RTU that uses the same transport protocol as your current systems and can be integrated within the existing system.