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What is common-mode voltage in RS485?
The common-mode voltage range for RS-485 is expanded to −7 V to +12 V. The RS-485 transceivers must withstand this common-mode voltage range while tristated (disconnected from the bus). An RS-485 system must have a driver that can be disconnected from the transmission line when a particular node is not transmitting.
What is common-mode voltage in inverter?
In an inverter-driven system, the common mode voltage (Vcom or VN-G) can also be defined as the voltage across the stator neutral (N) and the DC bus mid-point (M) because from a high-frequency viewpoint, the DC bus mid- point (M) is same as the electrical ground (G) of the system.
What is common-mode output voltage?
(1) The average of the voltages at two output terminals of a circuit. (2) The ac voltage between two output terminals (or the output terminals and ground for circuits with one output) when ac signals of identical phase and amplitude are applied to the input terminals. JESD99B, 5/07.
Can a RS-422 / 485 link be grounded?
In Summary: A partially isolated RS-422/485 link generally is locally grounded and would not have a direct ground wire between the two ends. It still relies on external surge protection to divert the inevitable common mode surges to ground. The ultimate form of isolation with metal wires is full galvanic isolation.
What is the common mode range of RS485?
RS485 extends the common mode range for both drivers and receivers in the “tri-state” mode and with power off. Also, RS485 drivers are able to withstand “data collisions” (bus contention) problems and bus fault conditions.
What’s the difference between RS485, RS232, and RS423?
Standards have been developed to insure compatibility between units provided by different manufacturers, and to allow for reasonable success in transferring data over specified distances and/or data rates. The Electronics Industry Association (EIA) has produced standards for RS485, RS422, RS232, and RS423 that deal with data communications.
Can a RS-485 transceiver create its own virtual ground?
The RS-485 transceiver will function with its “virtual ground” provided no more than just a few volts of common mode voltage are present. Beyond just a few volts, the limits of the transceiver’s ability to create its own virtual ground are exceeded.