Allen Bradley PLC type SLC 5/03 has two models, namely, modular and Fixed (compact) models. Modular type is shown below:
Modular types consist of shelves (chassis), power supply, processor (CPU), and I / O modules. The Compact type consists of a fixed installed power supply, processor and I / O, all of which are packaged in one unit.
Power supply:
For modular type PLC, there must be a power supply on each rack. Excessive loading on power or power will result in rapid damage. Therefore, choosing the power supply must be careful, namely by calculating the required power requirements in accordance with the hardware configuration.
There are three types of input voltage that can be connected to the power supply. For input voltage 120/240 VAC can be selected using a jumper (place the jumper in a place that matches the input voltage). As for DC voltage, the input voltage is 24 Volt DC. For more details, note the specifications of the power supply used in the PLC SLC 500 type modular.
Processor (CPU):
The function of a processor is to control and supervise all operations in the PLC. An internal communication in the form of an Internal Bus carries information to and from the processor, memory and I / O units both under CPU control.
The SLC 5/03 processor has a key switch located on the front panel that allows us to be able to choose one of three options, namely: Run, Program, and Remote. All three positions are explained below:
RUN position
In this position, the processor executes a ladder program, monitors Input equipment, monitors output equipment, and can also do forced on I / O. Here we can change the processor mode by changing the position of the key switch to the RUN position. In this mode we cannot edit the program.
Program position:
In this position, the processor does not execute the ladder program, and the PLC output does not work. In this position, we can edit the program.
To change the processor mode to the PROG position, that is by changing the position of the REM or RUN to the PROG position. If the position of the lock switch is in the PROG position, we cannot change the mode of the processor through the programming tool.
Remote position:
In this REM position we can change the position of the processor mode from or through a programming tool and can also edit temporary ladder programs between PLCs with programming equipment in online conditions. To change processor mode to REM position by changing the position of the lock switch from the RUN position or PROG to REM position.
I/O Module
Input and output modules are interfaces that are used to censor and activate a machine or control system. There are two types of I/O if we review them from the system, i / O modules for digital signals and I / O modules for analog signals.
Digital I / O Module
The digital module has been designed to be able to adjust the voltage and current levels in accordance with the voltage control system components. Thus, by using this digital module we can directly connect the signal through the terminal on the front panel of the I/O module.
Analog I/O module:
PLCs can also process analog signals significantly. This analog module can be used to handle basic tasks in closed-loop control systems, such as examples of automatic level control, speed control, etc.
Allen bradley PLC Chassis:
Type of modular PLC. The power supply is installed at the far left position on the frame. The processor module and I / O modules are installed on the right side in sequence.
All components can be easily installed into the framework because in the framework there is a guide flow that can guarantee the components are installed correctly. No special equipment is used to insert and remove components from and to the framework