Title:

Industrial System Company


Description:

Developed process control software for the BHP steel rolling mill at Hastings. A global image of the state was maintained with each PLC's exported variables being accessed across the network. Both Ethernet and Arcnet access was available, the former for PC's and the latter for Motorola 68000 processors on a VMEBus rack and PC's were attached to the Arcnet cable. The Motorola chips ran the OS9 real time operating system.

The project involved writing two Yacc parsers; a send-receive protocol based on an in-house message port system and a real time image-viewing tool. The first parser read a global configuration file, which showed for each node on the network the range of mill signals that it controlled. Each node would parse this file and determine how much global data was required to keep an image state of the mill. The other parser was a data-dictionary which provided a high level interface to modify and monitor each of the signals.

An API library was written which could reference each signal based on their data dictionary tag names. The software on the PC was implemented as a TSR and on the OS9 system a shared memory module was used to allow multiple processes to manipulate the mill signals. An Arcnet driver was prepared for a PC to send and receive packets on the CC150 Arcnet card. The software is written under Borland C++ V3.1 and was then ported to the OS9 environment .