Outputs Under OMS or MSS Outputs created when using OMS or MSS (via Metro’s Make outputs reflect current studio setup document option) are created on a one-to-one correspondence to the number or output device channels you’re using, and are automatically named with the corresponding device name, as defined in the Current OMS or MSS Studio Setup document. You can rename OMS or MSS Outputs if you wish, and you can delete Outputs or add new ones. You can have up to 254 Metro Outputs derived from your Current OMS or MSS Studio Setup document.