Like a PLC, the ICU handles digital inputs, logic functions and outputs simply and reliably. Unlike a PLC, the ICU is also able to handle complex analogue functions simply, elegantly and very cost effectively. Fitted with up to 40 modular mixed analogue or digital input/output channels, the ICU provides 8 PID loops, 6 profile generators and 50 "IF/THEN/ELSE" function blocks that can operate on numerical variables or on logic functions. The plain English menu driven Windows set up software (screen shots shown below) package can be learnt in a few minutes and can be up/downloaded via an infra-red link to a lap-top PC or via a communications port. RS485 or 422 serial communications to an optional PC based supervisory system (e.g. Data Manager) provides the operator interface and long term data storage.
The ICU will enable control systems integrators and machine OEMs to create a complete control system with just one piece of hardware. Compared with a Christmas tree of process or temperature controllers and a PLC, this saves on installation and wiring time, plus the very considerable cost of writing custom communications routines to enable units from different manufacturers to communicate.
Using the ICU, a typical heat treatment furnace control package could be configured with multiple profilers storing product recipes, feeding up to 7 zone controllers cascaded with a work piece temperature controller in Thermal Head Ratio mode. Further thermocouples could be fitted to monitor for surface overtemperature on the workpiece, with alarms set for both safe maximum temperatures and for deviation from the current set point. Safety and functional interlocks such as injecting purge gases could be controlled automatically, or via manual operator controls interlocked with appropriate product recipes, temperatures and pressures in the furnace. The operator interface and batch record historian could be provided by a PC SCADA package such as FGHs Data Manager, or a third party package such as Wizcon or FIX.
The ICU's firmware is supremely flexible. For example, any input can be scaled and characterised to accept 4-20mA transmitters or direct connection to primary sensors such as thermocouples. Inputs can then be assigned to PID loops, IF/THEN/ELSE function blocks or calculation blocks that determine highest, lowest, average, spread etc. The profile generators support 5 ramps expressed in digits/hr and 5 dwells in decimal hours per programme. Each has control inputs for start, stop, pause and outputs for running, ramp up, ramp down and dwell conditions. Any profile input/output can be assigned to an internal (virtual) logic point or direct to a hardware I/O channel. Dedicated analogue monitor blocks check for correct operation of sensors and output devices without using up more generalised function blocks.
The ICU's hardware is supremely flexible. To optimise the hardware costs, ICU can be sub-equipped to match the needs of each application. Five I/O module slots are provided, and each can be fitted with any of the following 8 channel modules making 40 channels in total. Voltage/thermosensor analogue input, current analogue input, resistance analogue input, current/voltage analogue output, thermocouple output (i.e. the ICU regenerates a thermocouple signal for connection to other ICUs or to discrete instruments), high voltage digital input (up to 250VAC), low voltage digital input, relay output and solid state output.
To give increased power to the programmer, the IF/THEN/ELSE function blocks support a variety of IF operations including A=B, A<B, A>B, A and B, A or B, A xor B and a variety of THEN operations including A=B, A = B+C, A=B-C, A=B/C, A=BxC, A=B and C, A=B or C, A=B or C. The values for B and C may be registers or constants.
Each of the four calculation blocks allows any or all of the 40 variables to be compared. Virtual outputs are generated representing highest, lowest, average and spread of the channels assigned to the block. The virtual outputs can then be connected to controllers, other function blocks or output via one of the hardware I/O channels. These blocks allow the programmer to perform easily quite complex operations such as controlling on the highest variable in a group, or generating an alarm if the lowest in a group deviates from the average by a set amount.
The ICU measures just 255x178x101mm and weighs under 2kg.
If you require any further information on the ICU, or would like to know if it can be applied to your system, please E-mail us or contact one of our sales engineers on the telephone number above.