The maximum cable length supported by ST485BD depends on the baud rate and the type of cable used. As a general rule, the maximum cable length is around 1200 meters at 9600 bps, but it can be shorter at higher baud rates. It's recommended to consult the application note AN214 from STMicroelectronics for more information.
To ensure reliable communication over long distances with ST485BD, it's essential to follow proper cabling and termination techniques. This includes using shielded twisted-pair cables, terminating the bus with a 120-ohm resistor, and using repeaters or line drivers if necessary. Additionally, implementing error-checking mechanisms and retries in the communication protocol can help detect and correct errors.
Yes, ST485BD can be used in a multi-point or multi-drop configuration. However, it's essential to ensure that the total bus capacitance does not exceed the recommended maximum value of 270 pF. Additionally, the use of repeaters or line drivers may be necessary to maintain signal integrity and ensure reliable communication.
ST485BD is not designed to handle hot-swapping or hot-plugging. It's recommended to power down the device before connecting or disconnecting it from the bus to avoid damage or data corruption. If hot-swapping is required, consider using a transceiver with built-in hot-swap capability or implementing external circuitry to handle the power sequencing.
ST485BD has an ESD protection level of ±2 kV according to the IEC 61000-4-2 standard. This means it can withstand electrostatic discharges up to 2 kV without damage. However, it's still recommended to follow proper ESD handling and protection procedures when handling the device.
ST485BD datasheet
by STMicroelectronics
