FTDI Community
General Category => Discussion - Hardware => Topic started by: ivanooi on December 12, 2020, 03:09:04 AM
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Hi all ,
I am using ft4232 as converter to rs485 and I have some questions :
1) can I configure the txden = ri enable without the need for an eeprom ?
2) I have the usb to rs485 plus four evaluation module and wondering do you have the schematic for that board?
3) why for rs485 module local echo is enabled?
Thanks
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Hello,
In order to configure TXDEN, an external EEPROM is required:
* RI#/ or TXDEN is selectable in the EEPROM. Default is RI#.
I can provide the USB-COM485-PLUS4 if you contact us via email:
https://www.ftdichip.com/FTContact.htm (https://www.ftdichip.com/FTContact.htm)
RS485 systems often have local echo enabled. This means any data transmitted by a device is echoed back to itself.
There is a hardware option to disable local echo on the USB-COM485-PLUS4. Please refer to the USB-COM485-PLUS4 Datasheet (https://www.ftdichip.com/Support/Documents/DataSheets/Modules/DS_USB-COM485-PLUS4.pdf).
Connect pin7 and pin 8 can disable the local echo function. The local echo is enabled by default.
Best Regards,
FTDI Community