EUROTHERM’s 2500 System uses a flexible modular ‘building block’ concept of great flexibility to bridge the gap between accurate local analog control systems and more complex digital process control architectures.
It incorporates a number of unique hardware and software interactions that provide fast, accurate response times for analog process and machine control systems.
The system provides high performance, high accuracy and exceptional functionality in an I/O system, with cost effective access to a wide range of advanced functions. These include PID control with auto tuning and gain scheduling.
Designed to communicate with any Modbus, DeviceNet or Profibus master, the system can be used as a stand-alone control system or as remote I/O for signal conditioning, alarm monitoring, remote data acquisition or devolved control for systems such as PC based SCADA packages, text and graphical HMI interface screens and PLCs.
The 2500 system is available in three base sizes, taking 4, 8 or 16 I/O modules each - allowing for up to 32 analog and 64 digital inputs and output.
Up to 16 bases may be daisy chained to provide acquisition and multiloop control solutions for up to 128 loops. DIN rail or panel mounting allows the 2500 to be located where the control action is required, minimising the cost of the cable used, as only the communications need be taken to the user interface.
Each control rack contains an I/O controller featuring eight high stability PID blocks, which provide an extensive range of control strategies.
Each PID block offers one-shot auto tuning to optimise control performance without the need for specialist knowledge. Every PID block may be a single PID, cascade, ratio or override controller, each providing the choice of analog, time proportioned or valve position output.
When used as a cascade loop, the auto/manual function works on both loops allowing bumpless transfer between auto and manual while in cascade mode.
The control module in each rack is capable of running up to eight multiple, single or compound loops while operating at 9Hz (110ms).
Override control allows for the implementation of advanced control strategies such as auto profiling and thermal head control. This would allow the analog input to set the maximum output that the loop can produce.
Advanced features include mathematical functions and combinational logic such as AND, OR, XOR, latch, equal, not equal, multiply, divide, high/low signal select, square root, greater than, less than, log, average, sample and hold etc.
Advanced functionality such as ‘hot swap’ allows automatic switching to a back-up sensor if the primary input signal fails. Other functions include user value constants, timers with 4 modes of operation (pulse, off delay, minimum on and one shot), counters and totalisers.
The totaliser blocks can be used to measure the total quantity of a measurement integrated over time (e.g. flow, power). Outputs from the totaliser block are the inputs integrated value.
An alarm state and pulse output for wiring to a counter block or external electromechanical counter are available to extend the upper range of totalisation.
The soft wiring concept provides the ability to make a ‘connection’ between a node inside the controller and an I/O signal such as a digital input or an analog output. For example, an analog input signal can be ‘soft wired’ to the maximum power output parameter on a control loop output.
A wide variety of I/O modules allows for any combination of analog or digital I/O. Universal scalable and software selectable, dual, triple and quad analog input modules accept thermocouple (J, K, T, L, N, R, S, B and P), RTD (Pt100, Cu10), potentiometer, voltage, milliamp and millivolt inputs.
Non-linear or non-standard curve inputs can also be up loaded. 24V dc auxiliary is provided for loop powered inputs. Analog outputs are software selectable between voltage and milliamp outputs.
Multi-channel digital I/O (contact, logic and ac mains input [115/240V ac]) modules are provided for all pulse, switching, totalisation and alarming I/O requirements.
A user friendly Windows-based configurator package, 'iTools' is used to set up the 2500 using MODBUS RTU communications, and provides a simple visual and file based structure to commission the I/O points, analog and digital I/O combinational logic and mathematical calculation requirements, PID function blocks as well as interconnecting the different variables, alarms, function blocks and I/O using internal 'soft' wiring.