Introduction to Toshiba PLCs for industrial process control and automation

PLCs (Programmable Ladder-logic Controllers) are well established in the Market Place, and are suitable for most applications ranging from simple control through to the most demanding process control requirements. Toshiba’s family of PLC’s can be programmed in various languages, but still the most popular is “Ladder Logic”. Ladder-logic is a language that looks (and acts) like an electrical ladder diagram. Ladder-logic is not only a self-documenting-graphical language, but the fastest way to get one-of-a-kind applications up and going. We call Ladder-logic a self-documenting language because when you are finished, you can print out a copy that your plant electrician can read and understand! Why? Because it uses the same graphical representation that electricians call ladder diagrams with the same types of symbols they have been looking at for generations.

PLC’s traditionally come in 2 formats , Brick style & Rack Mounted

Brick type PLC

A 'brick' PLC has a block shaped case (hence a 'brick') with terminal strips on it. They can be panel or DIN rail mounted but come in a model-number-determined set of I/O capabilities

Rack type PLC

A 'Rack' has one or more 'card racks' that individual circuit cards slide into so you can pick and choose your I/O to whatever number and/or type you need. (There is the exception with some of the T1 series of bricks - some also have a way to add a few extra cards and yet another connection so you can add a real rack!)?

Toshiba’s PLCs have both RS232 & RS485 ports, allowing the user to read/write to any of the internal registers very easily. (for more information see the Computer Link page ). . There are third party software packages that provide HMI interfaces as well as LCD touch screens. The protocol is a simple ASCII format. You can access and set the information with any program language. There are also high speed networking capabilities available. Several third party user interface packages support it - or just write your own to run on a PC - it's simpler than you think. For more information download the computer link manual. And the modem control manual.

Why Toshiba PLCs?

First, the software programming package is the same for bricks, Racks and advanced T & S series PLC. If a brick project gets larger the program can be easily transfered to a rack or advanced system. This also means that you only need to learn one software package.

Toshiba is known worldwide for their extremely high MTBF of their PLCs besides the excellent programming software. Toshiba uses these PLCs in their semiconductor and consumer electronic plants, which we believe, caused the creation of a far above average software environment and extremely high quality product.

Toshiba PLCs were originally designed for internal use in Toshiba factories. The engineers who design the equipment had to use it. Interestingly when the engineers have to use their own equipment, good things happen. Combined with excellent design and reliability, is the great software. The windows based software makes programming just a matter of dragging and dropping the symbols into place. If you want the best in a laptop you ask for a Toshiba - if you want the best in a PLC ask for Toshiba.