FATController

In 2002 CMA introduced it’s Four Axis Total Controller after a 2 year development process. FATC offers an unmatched combination of processing power, software flexibility, standard I/O, and value when compared with other real-time controllers available.

A question we are often asked is “why a real-time controller – why not use a PLC ?”. The reasons why PLCs are not applicable for closed loop control of hydraulic equipment include:-

  • Processing power. Modern hydraulic real time controllers operate typically no slower than 2msec per software iteration (or sample period).
  • Software functions. While many PLCs have ‘PID Control’ software functions, modern hydraulic controls usually benefit from other more complex mathematical functions.
  • Trajectory generation. Similar to servo drives, the job of the real-time controller is to generate a motion trajectory to ensure smooth and accurate motion from the actuator. This trajectory may include S-curve profiling, trapezoidal profiles, or even multi-loop profiles, and all these may need to be ‘stitched’ together during operation (e.g. moving from constant speed to deceleration)

The validity of these devices is evidenced by the many types available from various manufacturers.

In 2006 FATC was updated and has the following features:-

  • Up to 4 axes controlled by a single controller.
  • 8 off analog inputs. 0-20mA, 0-5V, +/-10V
  • 4 off analog outputs. +/-10V, 10, 20, or 40 mA.
  • 12 off opto-coupled digital inputs, 6 off relay outputs, and 6 off transistor outputs.
  • 2 off SSI (digital transducer) inputs.
  • 2 off Quadrature (incremental encoder) inputs.
  • Multiple serial ports, with Modbus networking standard.
  • Optional EtherNet, DeviceNet or ProfiBus networking.
  • Optional Touchscreen range.
  • Sample periods down to 0.5msec.
  • Programmed in C, using Metrowerks CodeWarrior, and CMA software drivers, header files, and software template.
  • ‘PCMaster’ Interfacing software (see picture) for tuning, datalogging, troubleshooting and maintenance support.

FATCs have been used in many different applications, either as a stand-alone controller, or as a slave to a local PLC or computer. Applications include presses, test machines, conveyors, flying shears, and customised manufacturing machinery.