Max232 is integrated circuit device which was first created in 1987 which is used to convert the signal from Rx232 serial port to the suitable signal used in TTL- compatible logic circuits. These Max232 is a dual transmitter as well as dual receiver that typically convert RX, TX, CTS, and RTS signals.
This phrase we regularly hear in industries. It is serial data transmission or it is form of communication. Most of people refer it as a serial connection. It is most used form of data transmission. RS232 transmit the signals using positive voltage using binary 0 and negative voltage using binary 1. It is capable of converting 5V TTL logic level to TIA or EIV-232-F level and can take up to +-30V input.
So generally this MAX232 is used to communicate between the micro controller and PC or laptop. But in PLC use this RS232 to talk to other modules or even other PLCs. This module can be any communication device such as operator interface or HMI, computers, motor controllers or drivers, A robot, or some kind of vision system.
There are two different types of RS232 devices
- DTE (Data Terminal Equipment).
- DCE (Data Communication Equipment).
The Pin diagram of MAX232 is given bellow
Structural view of RS232
So we can use MAX232 to convert TTL i.e. transistor transistor voltage level to RS232 and vice versa. If we want use MAX232 we have to design its small basic circuit in which it must have 4 capacitor of 1µF. the different application such as computer, modem, battery powered system, etc. are commonly used this MAX232 and RS232 to communicate with each other this MAS232 pin out consist of 16 pin and the first 6pins are used to connect capacitor while the next 8 pins are used for serial port connection and the last 2 pin are power pin as shown in figure.
Transmission capability of RS232
- RS232 can transmit or receive the data rates up to 20 kbps with distance range capability is around almost up to 50ft. it is depend on the capacitance of the cable. Thus the low capacity data can transfer data up to 1000ft while the cable with high capacitance can transfer data at lower distance.
- The communication is based on the transmission and receiving protocol and it has total 9 pins in carrying out the complete transmission. The above image shows the representation of the RS232. Thus this communication is carried out between DTE and DCE terminals over the mutual agreement for the data transfer. When it is turn ON, it indicates that the DTE terminal is ready to transfer the data. The data will transmitted gradually over the line without any disturbance if the CTS pin from the other is activated and of permission is given to DTE for data transfer.
Application of MAX232
- Battery Powered RS 232 Systems
- Interface Translation
- Low Power Modems
- RS 232 Networks (Multi-drop)
- Portable Computing
Application of RS232
- DNC for CNC
- Receipt Printer, POS
- PLC control
- Sensor Data Com.
- Robot, etc.