Posted 26 Dec 2019 (edited) hi all, I am using SCU32 ( unit1, port2, 2wire and termination OFF) to get the RS485 data strings from the compass with setting 19200bps, 8 databit, 1 stop bit & No parity. I can send the TX string ( 01 03 00 01 00 03 54 0B) from D100 memory and write the Rx data to D2000 (01 03 06 xx xx yy yy zz zz CC CC). But the whenever the there is no RX data, The TXdata bounce back to RX. (refer to video, d100 is TX, D2000 is RX). I also tried wth SCU32 termination resistance ON. Same thing. I am not sure what is missing. Should i use different logical Port for TX and RX ? EDITED: Just tried another scenarios 1) removed the connector and tried , D2000 - was written the TX values 2) Disable the RX changing LD from P_On to P_Off. D2000 - was written to #0000 0000 0000 0000 I am not sure what is happening., Open connection also TX data bounce back to RX Appreciate all help Thanks a lot video1.mp4 Edited 26 Dec 2019 by T J SHARON Share this post Link to post Share on other sites
Posted 9 Jan 2020 Just noticed that 'No protocol; doesn't work with 2 wire connection. So i will try to use cx protocol Share this post Link to post Share on other sites
Posted 9 Jan 2020 You shouldn't split threads, because people won't see both. I don't know what cx protocol is, but some RS-485 devices need physical jumpering for half duplex operation - where the Tx negative is jumpered to Rx negative, Tx positive is jumpered to Rx positive. Share this post Link to post Share on other sites
Posted 10 Jan 2020 I would try turning off CTS control (Port 2 settings) I have no idea what 1:N protocol is, do you? Given how close it is to Modbus, can you try Modbus RTU protocol? Share this post Link to post Share on other sites