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SQ25:MODBUS protokol- how read answer?

alexeyustinov
Wed, 31 Jul 2019 05:32:17 GMT

Hi! I try to read data from device via Modbus RTU protocol. I configured channels 1 and 2 as output and connected to the buses A and B. The request was created normally, after it the device answers on the same buses. How to me to receive the answer? It is advisable to change channels 1 and 2 after forming of the request to input to receive the answer.

Ibrahim KAMAL
Mon, 05 Aug 2019 12:13:26 GMT

Hi, I'm afraid it's not as simple as that. If you wish to emit and receive data on RS485 bus, you need a transceiver. You can connect one SQ output channel to the transceiver data input, another SQ output to the DE (drive enable), and finally, you can listen to the bus with a 3rd SQ input channel. Does that help?