digital output modules plc, which has several types, characteristics

igital output modules plc, which has several types, characteristics
According to different driving circuit, the digital output module can be divided into the following three categories:
High-power transistors and FET type - mainly used to drive DC loads.
Triac type - mainly used to drive an AC load.
Small relay type - used to drive AC or DC load, a contact signal outputplc digital input.
Switch if there is merit flexible output relay output AC and DC load large, slow to respond shortcomings
Advantages of fast reaction transistor output, shortcomings DC output, current, voltage is small.

plc modules in several categories

programmable logic control plc because of its high reliability, simple programming, versatility, small size, compact structure, easy installation and maintenance, etc., and in industrial control has been widely used. PLC modules are generally divided into the following categories:digital output module, analog input modules, analog output modules. In industrial control especially in the field of process control analog acquisition and control needs a relatively large amount, so the PLC analog input and output modules require more, and analog input and output modules are more expensive, increasing the analog input, output modules increases the cost and reduces the cost of the entire system, limit the application of PLC. This paper presents a simulation based on the amount of communication of input and output expansion module method seeks to solve this problem.

Determination the number of analog output module

In the right FX series programmable controller basic unit can connect up to eight special function modules, plc controller suppliers ,which are numbered from the one closest to the base unit begins sequentially numbered from 0 to 7. This configuration uses FX2N48 point basic unit, connecting FX-4AD, FX-4DA, FX-2AD 3 block simulates modules, their numbers are numbers 0,1,2. This does not affect the right of the three modules extend the number two, but it will affect the total input and output points. 3 analog modules occupy a total of 24 points, digital output plc  then the basic unit and expansion of the total input and output points can only have 232 points.