Exploring PLC types
Based on the hardware specifications, there are two basic types of PLC:
- Compact
- Modular
Let’s have a look at each of the types.
Compact PLC
In this, the CPU, input module, output module, and sometimes the power supply are integrated into a single module.
It has a fixed/limited number of I/O by default, but some are designed to support expansion modules, which can be added to increase the number of inputs and outputs. A compact PLC can also be referred to as a fixed or integrated PLC. S7-200 and S7-1200 are examples of compact PLCs by Siemens, while FX 1N, FX2N, and others are examples of compact PLCs from Mitsubishi. Other PLC manufacturers also have their compact PLC series/models.
The following figure shows a compact PLC from Siemens (S7-1200, CPU 1211C, AC/DC/Rly):
Figure 7.7 – Compact PLC from Siemens
The credit for this figure goes to Showlight Technologies Ltd. (www.showlight.com.ng...