As of release 1.2, the RM-U and RM-C share the same firmware under the collective name RM-x with the same functionality. Differences between the RM-U and RM-C will only be explicitly indicated where they exist.

RM-x Release Notes 1.21

• RM-C/2 transparent mode and bootloader transparent mode control both RS485 channels
• With the RM-U, the RS232 interface can now also be used while the USB interface is connected
• Support for 126-step speed and F13..F28 control (requires iTrain 3.3.3)
• Implementation Protocol 3.12
• Significant code adjustment. The internal handling of DCC packets has been completely changed to make room for 126-step speed and F13..F128 packets and to prepare for a different method of block-linking (future development).

Please note:
If you install RM-x 1.21, iTrain 3.3.3 expects the Dinamo system to support the DCC Emergency Stop function.
Therefore, when using RM-x 1.21, at least TM44 1.11 and/or TM-H 5.11 must be installed.
If you have an older version of TM44 or TM-H, you cannot use RM-x 1.21