Circuit Schematic RS232 to RS485 Module

Eltronicschool. - Do you want to build your own RS232 to RS485 module in this time? in here we will give you circuit schematic of RS232 to RS485 Module that has published on Electronics-Lab site that authored by Rajkumar Sharma.

Circuit Schematic

Figure 1. Circuit Schematic RS232 to RS485 Module
(Source: Electronics-Lab)

Component Part

Description

Circuit schematic like in figure 1 above is Circuit Schematic RS232 to RS485 Module using main IC components are MAX232 and MAX485. An Onboard 9 pin female “D” connects this PCB to the Serial Port cable (not supplied with the Kit). Connector J1 and J2 provide the MAX232 IC input/output (IO) and Connector CN1 provide MAX485 IO. An optional Power Supply section can provide regulated 5V DC to the circuit and can be included to power by bridging Jumper J4. LED D2 provides visual indication of power on this board and Diode D1 prevents against reverse polarity connection of power supply at J3. 

This circuit can also work on 5V supply from the host interface which can be provide through J1 in which case you need to remove Jumper Link @ J4. Connector J2 provide extra connection of the other set of level shifter with in the MAX232 IC.

RS485 cable is to be connected at Connector CN2 and are impedance matched with Components R3, R1 and R4. Terminal marked “A” on CN1 is the Receive / Transmit control Pin for the RS485 flow control. Pulling this pin to Gnd will enable the Receiver on the RS485 and Pulling it High (connecting it to Vcc) will enable it to work in the transmit mode. To know more about project of RS232 to RS485 Module, you can use this [Link].