How is RS485 implemented in a USB converter?
The USB/RS232 converter generates a sequence from its TX pin. STM32F407 receives this character, and simply echoes it via its TX pin. MAX485 ic receives this character, converts it a differential signal. Other MAX485 ic gets this differential signal and converts to the character.
Can a MSP430 LaunchPad communicate with a RS485 chip?
Here we are going to interface a MSP430 Launchpad with a RS485 transceiver chip like MAX485 and communicate with an x86 PC. Serial (TTL) or RS232 protocol is fine if you are planning to communicate over short distances of a few meters,when you increase the range to a few 100 meters RS232 protocol will become inadequate.
How is MSP430 connected to max485 chip?
UCA0TXD pin of MSP430 is connected to DO (Driver input) pin of MAX485. P2.0 is connected to DE (Driver enable) pin of MAX485 which is used to put the chip in Transmit Mode. P2.1 is connected to ~RE pin (Active Low) of MAX485 which is used to put the chip in Receive mode.
When to use RS485 for long distance communication?
Serial (TTL) or RS232 protocol is fine if you are planning to communicate over short distances of a few meters,when you increase the range to a few 100 meters RS232 protocol will become inadequate. For long distance wired communication you have to use a different protocol called RS485 which can communicate over a kilometer.
What to do with pull up RS485 drivers?
The pull up/down will load the network and add stress to RS485 drivers, try use token passing methods to transfer the master mode (transmitter) between devices if the nodes are far apart much exposed to environment use this document to protect your network
What does it mean when RS485 is impedance matched?
RS485 is impedance matched; that means that the driver can be seen as a perfect driver followed by a resistor, which has approximately the same resistance as the termination resistor (exactly the same in the ideal case).
Which is not allowed in the RS-485 specification?
The RS-485 specification defines the driver’s output current and voltage; transmitting 12 V is not allowed. (The transceivers don’t actually output the full V CC to the bus, but a high current is the price you have to pay for reliable communication over long distances in noisy environments.)