• Quick/Low Cost Installation
• Safe Area or Zone 1 operation
• Ideal for retrofits or upgrades
• Information presented in MODBUS format

The system links control valves on 16 tanks in remote locations around the site back to a central and off sites and blending control room. The tanks are all crude tanks and the system is used to control oil movements. Future expansion to finished product tanks would facilitate automatic blending control.

The system is based on standard PACSNET 3000 equipment and 458 MHz band low power UHF radios transmission. PACSNET 3500 outstations are hardwired to the actuators and a 3530 receiver station links serially using MODBUS RTU protocol into a Siemens PLC.

The tanks are organised in groups with a control valve (modulating) and actuator on each. Each group of 4 actuators is managed by one outstation and there are four groups. The actuators are in cubicles outside the bund wall and the outstations are located adjacent to them. An end fed dipole is used on the outstation to radio back to the receiver. In this application the area outside the bund is of a general purpose electrical classification.

The PACSNET system can be used with a wide range of actuator types and makes. Also, if required, the system can be located in environments up to Zone 1 classification. It adheres to the British standards on the use of radio in hazardous environments.

The PACSNET system uses several levels of security features to ensure radio communications are good and that data transmitted is accurate and reliable. With the benefit of these features, the use of radio in such high profiled locations is now accepted.