RS485

1 Overview

RS-485 在多数情况下，由于应用环境的恶劣，需采用隔离方案以防止出现接地环路。

光耦隔离电路占用空间大，需要分立元件、缓存驱动， 但成本便宜

2 Hardware

2.1 MAX485

Need B0505 DC-DC and PS2501

• RS485_1_A+ --- MAX485_PIN6
• RS485_1_B- --- MAX485_PIN7

• MAX485_PIN4 --- ARM9_CORE_J2_68_TXD0
• MAX485_PIN1 --- ARM9_CORE_J2_69_RXD0
• MAX485_PIN2 & 3 --- ARM9_CORE_J1_69_PC30

2.2 ADM2483

Also need the B0505 DC-DC

2.3 ISO3082

Also need the B0505 DC-DC

2.4 ADM2587