Intelligent Upgrades for Tomorrow's Factories: Smart, Energy-Efficient, and Highly Reliable RS-485

Intelligent Upgrades for Tomorrow's Factories: Smart, Energy-Efficient, and Highly Reliable RS-485

RS-485 belongs to the Physical Layer of the OSI model. Its electrical characteristics define a standard for 2-wire, half-duplex, balanced transmission line multipoint communication. This standard was issued by the Telecommunications Industry Association (TIA) and the Electronic Industries Alliance (EIA). Digital communication networks using RS-485 can efficiently transmit over long distances in noisy environments. In a multi-node bus configuration, multiple receivers can exist on a single network, making it ideal for industrial environments. The standard, TIA/EIA-485-A, was approved on March 3, 1998 [1]，Since then, RS-485 has been widely adopted in industrial applications as a communication interface.

Smart Upgrades for Tomorrow's Factories

The intelligent upgrades of tomorrow's factories will likely include demands for automation, energy efficiency, and high reliability. Amazing Microelectronic Corp. offers RS-485 transceivers that meet these requirements, as explained below.

1.      Automation: Polarity-Free RS-485

In industrial environments, new installations, troubleshooting, and maintenance can result in wiring errors by personnel. With traditional RS-485, if the A/B bus wires are reversed, communication errors occur. In long-distance wiring, finding and correcting all such mistakes can be time-consuming and costly. Amazing Microelectronic Corp.'s AZRS5485N RS-485 transceiver features a polarity-free design, meaning that even if the A/B wires are reversed, it can automatically detect and correct the error. This eliminates the need for manual correction or additional software configuration, aligning with the trend of smart factory upgrades. (Note: For the AZRS5485N transceiver, the master node requires pull-high and pull-low resistors on the A/B bus, while slave nodes do not. Please refer to the AZRS5485N datasheet for details.) Additionally, during installation or troubleshooting, the RS-485 bus may be exposed or come into contact with personnel. The AZRS5485N provides electrostatic discharge (ESD) protection, meeting IEC 61000-4-2 standards with levels of ±15kV (contact) and ±20kV (air), effectively protecting against static electricity and reducing equipment failure risks.

Table 1. Polarity-Free RS-485

2.      Energy Efficiency: RS-485 with Shutdown Function and 3.3V Power Supply

Energy efficiency has always been a priority in electronic product optimization. Amazing Microelectronic Corp. offers RS-485 transceivers that operate on a 3.3V power supply, including models AZRS3072, AZRS3076, and AZRS6023. The main difference between these models is their maximum data transmission speeds (AZRS3072 supports up to 250kbps, AZRS3076 supports up to 16Mbps, and AZRS6023 supports up to 60Mbps). 

In addition to compatibility with lower-power 3.3V microcontrollers, these models reduce output current during communication (with the same number of nodes on the bus). They also support Shutdown Mode (REB=Vcc, DE=0), with a maximum supply current (ISHDN) of only 10µA for AZRS3072 and AZRS3076, and 20µA for AZRS6023. Shutdown Mode allows smart factory systems to turn off unused RS-485 nodes, reducing power consumption and optimizing power loads, moving toward a greener, smarter factory. 

Regarding ESD protection, these models meet IEC 61000-4-2 standards with levels of ±15kV (contact) and ±18kV (air), as shown in Table 2.  

Table 2. RS-485 with Shutdown Function and 3.3V Power Supply

3.      High Reliability: RS-485 with High ESD/EOS Protection

Electronic equipment in factories is vulnerable to ESD (ElectroStatic Discharge) or EOS (Electrical OverStress) events, which can cause instability or failures. Amazing Microelectronic Corp. offers high ESD/EOS protection RS-485 transceivers, such as AZRS3082 and AZRS6534. The key difference between these models is their maximum data transmission speeds (AZRS3082 supports up to 115kbps, while AZRS6534 supports up to 8Mbps).

Both models offer superior ESD, EFT, and Surge protection, as detailed in Table 3. 

(Note: During IEC 61000-4-4 EFT ±4.4kV (5/50ns) testing, the current measured is approximately ±88A.)

*Note: In the IEC 61000-4-4 EFT ±4.4kV (5/50ns) waveform test, the current is approximately ±88A.

Table 3. RS-485 with High ESD/EOS Protection

As described above, Amazing Microelectronic Corp. offers RS-485 transceivers that are highly intelligent (polarity-free), energy-efficient (with Shutdown function and 3.3V power supply), and highly reliable (with high ESD/EOS protection) to meet the demands of smart factory upgrades. If you have related needs, feel free to contact us.

Reference: 

 [1] https://zh.wikipedia.org/zh-tw/EIA-485