EUROTHERM has released the Mini8 multiloop control and data acquisition system. It is designed to integrate with programmable logic controllers and other supervisory control and monitoring systems.
By devolving loop control to the Mini8 a PLC can concentrate on providing fast and effective logic control without the burden of running complex control algorithms.
The Mini8 has the same deterministic response and autotune features as Eurotherm's panel mount controllers. Implementing these functions reduces the hardware cost of the PLC, relieving it of the burden of performing analogue functions and often allowing a lower specification processor to be used. The feature set includes PID control and SP programming functions together with a range of features such as maths, logic and timing blocks. The system supports both the Modbus and Devicenet protocols, making it easy to interface with intelligent masters such as PLCs, HMI panels, DCS systems, master controllers and PC SCADA software.
The system’s four plug-in slots can accommodate a variety of I/O modules. Its feature set is ranged to suit simple multiloop and data acquisition applications and complex strategies including setpoint programming and mathematical and logical operations. Mini8 can multidrop on either Modbus RTU or Devicenet.
Setpoint profiles can be programmed to follow a series of time-based ramp and dwell segments. Each Mini8 can store up to 50 programs with an overall total of 200 segments. Digital events can be triggered in segments to interface to other parts of the control strategy or external devices.
The system uses a cycling algorithm and a current transformer input module. It can automatically scan electrical heaters connected to its logic control outputs and indicate heater partial load failure, over current or SSR short and open circuit. Heater current readings are also available to calculate power delivered to the load and make this information available to a supervisory system. Heater failure detection is compatible with single or three-phase load installations.
A range of toolkit functions can be used to create custom solutions and small machine controllers. Timing functions include a range of timers, counters and totalisers as well as a nonvolatile real time clock. Using the iTools drag-and-drop graphical wiring editor these strategies can be created and documented.
The system uses a fixed Modbus address table providing easy integration into PLC, SCADA and other third-party systems. Parameter addresses are fixed in one location. Both the Modbus RTU and Devicenet protocols are supported.
The Mini8 can be supplied with preloaded configurations to suit standard applications. It is capable of implementing complex control strategies. Eurotherm's iTools software suite provides a graphical function block view of configurations for easy creation, editing and debugging. A remote touchscreen LCD panel can be used to supervise multiple controllers. Standard screens enable out of box operation but still allow users to adapt screens to suit their own process.