INPUTS AND OUTPUTS
The PLC runs from a 12V DC power supply and also has 12V terminals on the box, so you may use the same power with the various sensors and output devices that you have wired up.
The relay driven outputs are very simple to use. Each of the eight outputs is accessed by a pair of screwless terminals on the top of the box. When an output is “on”, the relay connects the two terminals together, much like flicking a switch. Outputs can easily be wired to switch the on-board 12V power supply, or a separate power source could be used. For example, a 3V battery could be wired through an output to power a small motor. The outputs are isolated from each other and the PLC electronics, so a separate power source could be used with each output if desired.
The PLC offers eight optically isolated inputs. An input is sensed as “on” when a small current is passed between the common terminal and the input terminal (in either direction). Achieving this can be as simple as wiring a switch between 12V and the input, but the system also allows transistor based sensors, like opto-switches to be directly connected to the PLC. The inputs are configured as two banks of four, with a common terminal for each bank.
LED indicators, together with on-board push buttons for the inputs, allow experimentation without any external wiring.

LADDER LOGIC
Ladder Logic is the standard programming language of PLCs. TEP’s implementation of this graphical language, with intuitive names like INPUT1, OUTPUT3 and TIMER1, means that you can be up and running in no time (while simultaneously learning skills applicable to the real world).
The ladder logic diagram pictured shows one of the simplest programs you could create. The symbol on the left represents the state of INPUT1, and can be thought of as a switch that is closed when the input is “on”. The symbol on the right, represents the coil in the output relay, OUTPUT1. The Ladder Logic diagram can be thought of as a kind of circuit diagram, when the input is on, current is allowed to fl ow and the output relay is energised, it’s that simple. Programs are constructed as a series of rungs and hence resemble a ladder.
The included software provides a powerful, user-friendly environment to create your Ladder Logic programs. Available functions include I/O, timing, counting and much more. The same software is used to download the program to the PLC and monitor the PLC’s status via the USB connection.

FUTURE PROOF
The TEP PLC is equipped with four expansion ports to allow future input and output modules to be connected. Possible modules include, temperature sensors, motor controllers, analogue to digital converters and so on. An additional PLC can also be connected as a slave device, doubling the number of inputs and outputs.
Includes everything to get started: a PLC, power supply, tutorials, and a small selection of input and output devices.