RS485 And RS232 Debug Experience Sharing
Serial communication, especially RS232 and RS485, is widely used in industrial equipment. It has the advantages of strong compatibility, simple debugging, reliable operation, and strong on-site anti-interference ability.
But in actual use, the debugging work of RS232 and RS485 still made many technicians feel troublesome. In fact, we have some simple secret techniques. If we understand, we can use it to achieve great effect on debugging work.
RS232 serial communication has 3 points: 1) Is the transceiver line connected? 2) Is the baud rate consistent? 3) Is the flow control setting correct?RS485 serial communication has 2 points: 4) AB line connection right? 5) Is the baud rate consistent?
About the device's baud rate and flow control, can be set through software, in actual using scene, some GPRS wireless devices can read out the baud rate and flow control as long as they send a text message without moving the device.
Then the cable is wrong or not can be detected without moving equipment? of course can! Just know these 2 "cheats":
1) When RS232 is connected to two communication devices and powered on, serial cable 2-5 is measured.
, 3-5 byte voltage, two voltages are +/-3V or more, indicating that the connection line is right, if one of them is 0, then the transceiver line is reversed, (or broken), 2-3 exchange Just connect
2) RS485 is connected to the two communication devices, and the voltage between the two lines is tested under the condition of power-on. If the voltage is about 3V, it is normal. If it is 0, it is very likely that the two lines of AB will be reversed.