The arrival of the "PLC" was revolutionary.
My first brush with PLC's was with a Siemens which was installed at the car dumper in Dampier as part of an upgrade. Fault findimg on this was via a dedicated panel with a single line display. The system was housed in a Euro style card frame with power supply, CPU, memory, I/O cards and optional counter, timer and other function cards. This was, for the time, a very complex beast and a dog to fault find.
The 46Mtpa upgrade at Dampier in the mid 1970's saw a major revamp and extension. A new control tower, very similar to those at airports was built and one level housed multiple panels containing PLC equipment.
This was all Modicon, 184 & 384 gear utilising 200 series I/O.
The first SCADA system was also installed by Foxboro for this project. This consisted of a modified DEC PDP-11 computer with a serial connection to the PLC's.
Upstairs in the control room there were video status and alarm screens and a printer. In the day this was absolute cutting edge stuff. The computer was nicknamed "Claude" and could be a tad tempremental at times, especially so at month end reporting time.
The project also added a new stacker and an additional bucket wheel reclaimer, provided by IHI, both of which were equipped with Siemens PLC's.
The fines concentrator was added at Tom Price as part of the project and that also was all Modicon PLC's, including a 1084. This was a very rare beast. It effectively acted as a data concentrator for the other PLC's.
This is a work in progress and will be expanded, time permitting.
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