# /dev/ttyHS0 or /dev/ttyHSL0 **URL:** \ **Category:** Legato Application Framework\ **Created:** [November 28, 2017, 12:31pm UTC](https://forum.legato.io/t/dev-ttyhs0-or-dev-ttyhsl0/2822 "2017-11-28T12:31:01Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![TheGod](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/thegod/32/252_2.png) [@TheGod](https://forum.legato.io/u/TheGod)\ **Post date:** [November 28, 2017, 12:31pm UTC](https://forum.legato.io/t/dev-ttyhs0-or-dev-ttyhsl0/2822/1 "2017-11-28T12:31:01Z")
I use mangoOH green and UART1 uses file descriptor /dev/ttyHS0. I have to write program on FX30 and FX30 documentation says that UART1 uses /dev/ttyHSL0. Is it correct? I don’t have FX30 so I cannot check it. Does someone know if FX30 documentation correct? ---
**Author:** ![muralinagraj](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@muralinagraj](https://forum.legato.io/u/muralinagraj)\ **Post date:** [November 29, 2017, 10:13am UTC](https://forum.legato.io/t/dev-ttyhs0-or-dev-ttyhsl0/2822/2 "2017-11-29T10:13:37Z")
Hi, Yes, In FX30 UART1 uses /dev/ttyHSL0. Regards, Muralidhara N. ---
**Author:** ![CoRfr](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/corfr/32/69_2.png) [@CoRfr](https://forum.legato.io/u/CoRfr)\ **Post date:** [December 1, 2017, 2:27pm UTC](https://forum.legato.io/t/dev-ttyhs0-or-dev-ttyhsl0/2822/3 "2017-12-01T14:27:33Z")
On a mangOH green it would be HS0, which is a higher speed interface than HSL0. I don’t have the numbers in head, but HS it supports more modes than HSL. FX30 might not have integrated that feature (yet?). So on mangOH it should be ttyHS0 and ttyHSL1, and seems like both documentations are correct. ---
**Author:** ![TheGod](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/thegod/32/252_2.png) [@TheGod](https://forum.legato.io/u/TheGod)\ **Post date:** [December 1, 2017, 10:39pm UTC](https://forum.legato.io/t/dev-ttyhs0-or-dev-ttyhsl0/2822/4 "2017-12-01T22:39:11Z")
Thanks for information.