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Thought I may contribute the solution I found. (may aswell document it somewhere xD) I recently had to interface to two RS232 "slaves" connected to a single RS232 "master" which always iniciates communication and slaves which are adressed respond. Since RS232 is intended for point to point, I initially was going to convert to RS485 and create a bus in ...


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It's simple. Yes, you need a gnd connection so you can ensure common mode is not floating away out of the receiver ratings. The gnd connection may not necessarily be a good one, short or whatever, but it has to be there. The only exclusion is when you have some other weird way to ensure that it does not float, like maybe connecting gnd on one side to an ...


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As the tranceivers are not isolated, they allow for the bus wires to be 7V below it's GND pin and 7V above it's VCC pin. This means that there can be no more than 7V of potential difference between GND of this board and ground of the encoder. As this board has it's ground potential on earthed PC chassis via USB connection, it means that the encoder ground ...


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In short: A ground is not needed, because of RS485's characteristics. Isolation is in most cases best. TIA/EIA 485 specifies that no more than ±7V of potential between the grounds of two separate devices (shown as GPD below). The correct method for designing a differential data link is without ground wires. For ground potential differences higher than ...


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You should always have a CONNECTION (not necessarily a wire) since it is not galvanically isolated. No need for a dedicated ground wire though unless battery powered or one end is not earthed. That's what article you linked is saying. Does not matter. That's what decoupling capacitors are for. With RS422/RS485, parallel termination is used, so it goes next (...


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