ABB has extended its programmable logic controller (PLC) offering for industrial automation with a modular, scaleable suite of hardware comprising the AC500 PLC, S500 I/O module and CP500 HMI operator interface terminal - each of which can be purchased separately. The new system slots between ABB's existing AC31 PLC and 800xA distributed control system, and has been carefully designed to provide an easily expandable platform without hitting the customer with unnecessarily high initial costs.
The modularity is expressed in a choice of three CPUs (micro, mini and midi) offering increasing levels of processing capability and instruction memory capacity. These CPUs share a common physical size and connection so, when upgrading, there's no need to change the terminal base. I/O expansion, including decentralised expansion, is handled by the S500 units, which are effectively fieldbus neutral as they offer any one of five leading fieldbus protocols.
The CP500 HMI also offers a wide choice with no less than ten different displays, from a 2x16 character text display to a 10.4in TFT touch screen. Again, the functions offered by these HMIs depends on the customer's needs and budget. The full version, however, provides numerous functions, including moving graphics and an interactive touch screen display.