› M1 Support Forum › RCS TR16 HVAC Control Unit compatibility This topic has 1 reply, 2 voices, and was last updated September 22, 2021 at 6:12 pm by Brad Weeks. Viewing 2 posts - 1 through 2 (of 2 total) Author Posts September 18, 2021 at 12:59 pm #5577 Martin Multer Replacing an old X10/UPB stargate controller that interfaced with an RCS TR16 HVAC Control Unit. Is the M1 compatible with it? September 22, 2021 at 6:12 pm #5588 Brad Weeks It will require the M1XSP Serial Port Expander with Firmware 1.0.50 —- see M1XSP 1.x.xx Release Notes https://elk-manuals.s3.amazonaws.com/Release+Notes+M1XSP+Firmware+Standard+Version.pdf for more information Author Posts Viewing 2 posts - 1 through 2 (of 2 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In