# Why can't I specify RS485 functionality by adding it to the enum "peripheral\_operation\_mode" **URL:** \ **Category:** Kernel\ **Created:** [November 20, 2018, 5:37pm UTC](https://forums.freertos.org/t/why-cant-i-specify-rs485-functionality-by-adding-it-to-the-enum-peripheral-operation-mode/7532 "2018-11-20T17:37:23Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [November 20, 2018, 5:37pm UTC](https://forums.freertos.org/t/why-cant-i-specify-rs485-functionality-by-adding-it-to-the-enum-peripheral-operation-mode/7532/1 "2018-11-20T17:37:23Z")
**[larrydew](https://sourceforge.net/u/larrydew/)** wrote on [Tuesday, November 20, 2018](https://sourceforge.net/p/freertos/discussion/382005/thread/e8d536a113/#e40f): I have been scanning the forum and I can’t find a reason that RS485 support can’t be added to the USART functions. Do I need to manually call the “usart\_init\_rs485()”. By doing this will I automatically get half duplex control? I am using a sam4e micro. Thanks for any information. ---
**Author:** ![rtel](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/rtel/32/31_2.png) [@rtel](https://forums.freertos.org/u/rtel)\ **Post date:** [November 20, 2018, 9:17pm UTC](https://forums.freertos.org/t/why-cant-i-specify-rs485-functionality-by-adding-it-to-the-enum-peripheral-operation-mode/7532/2 "2018-11-20T21:17:04Z")
**[rtel](https://sourceforge.net/u/rtel/)** wrote on [Tuesday, November 20, 2018](https://sourceforge.net/p/freertos/discussion/382005/thread/e8d536a113/#e40f/5cd0): Sorry I can’t reply as I have no idea what you are talking about without any context. FreeRTOS itself does not provide RS485 functionality. [https://www.freertos.org/FAQ-how-to-use-the-FreeRTOS-support-forum.html](https://www.freertos.org/FAQ-how-to-use-the-FreeRTOS-support-forum.html)