Application 9

Application No.9 - Multiple Mixing Plant

This application deals with the control of a pair of PVC Mixing Plants,

but configured differently to Application 5

The project involved panel design, plc and SCADA application software, and on site commissioning.

Key components:- Mitsubishi AnS series PLCs, MelsecNet/B, Mitsubishi MX2000 SCADA software

Please scroll down to see more detail of the application

The central part of the system is a number of Mitsubishi AnS series plcs, communicating with each other over MelsecNet B. Each mixer's PLC then communicates via ethernet with it's own Mitsubishi MX2000 SCADA system..

One of the control panels existed before PJC Systems' involvement but the manufacture of the other panels was in house

What the plant does

This application deals with the control of two PVC mixing plants, mixing the material to be extruded to make window profile.

Mixer 1 was originally controlled by another company's control system. It comprised a Mitsubishi AnS plc and DOS based AMING graphics.

In 1997, PJC Systems were employed to control the new Mixer no. 2. The remit was to set up the control such that the Resin Silos (raw material) and Dry Blend Silos (finished product) could be shared by both mixers in the future.

PJC Systems configured the system so that all the items of plant which were to be common to both Mixers were controlled by a "common controls" panel, which, in turn, communicated with each mixer's own control panel via MelsecNet/B

All the plcs were Mitsubishi AnS series, and the graphics were (originally) Mitsubishi AMING, running under DOS. In 2001, PJC Systems upgraded the graphics to Mitsubishi MX2000 running under Windows, but left the rest of the control the same.

The factory manager could monitor both mixers from his office, but couldn't control either of them.

Batch data was logged to the factory manager's computer.

In 2004, PJC Systems also took control of the additives system which fed both of the mixers, added it to the existing plc network, and integrated it with both mixing plants.

(PJC Systems do not carry out any work beyond the SCADA system we install. All access to the factory network is to be carried out by the customer)