Protocol Number: 6 Autobind: No Channel Re-mapping: Yes Extended Limits: Yes Failsafe Support: No Receiver Match: Yes Telemetry: Yes - for TSSI and plugins Option Value: Number of channels (3 to 12), Enable Max Throw, Servo Refresh Rate (see Notes)
Models: Spektrum DSM2 and DSMX compatible receivers
Autodetect Format (a.k.a. the Auto sub-protocol) allows the radio to negotiate the correct protocol (DSM2 or DSMX), the correct number of channels, and the optimal data rate with the receiver. Auto-detection relies on telemetry working between the radio and the receiver.
If autodetection isn't working properly with your receiver (for example the number of channels is set incorrectly), you can un-check Autodetect Format and manually select the sub-protocol and number of channels.
For best results, set the sub-protocol to Auto for binding. During the bind process the receiver will inform the radio of the optimal configuration for sub-protocol, number of channels and refresh rate. When the bind ends the sub-protocol should have changed to one of the four DSM2 or DSMX options.
If you are unable to bind in Auto mode you can try all four sub-protocols manually.
A value of 3-12 will set the number of channels to that value
Adding 64 to the value will enable max throw (see Output Range)
Adding 128 to the value will enable 11ms refresh rates (see Servo Refresh Rate)
Adding 192 to the value will enable max throw and 11ms refresh rates
Receiver output will match the Spektrum standard throw, 1100µs to 1900µs
If using PPM Mode ensure that the
PPM_MAX_100 settings in _Config.h match your radio's output
The maximum output is 1000µs to 2000µs when using an input weight of 125%
Maximum throw can be overridden using the Enable Max Throw setting. In this mode use a channel weight of 84% to achieve standard throw.
To allow SAFE to be ON with a switch assignment you must remove the bind plug after powering up the RX but before turning on the TX to bind.
If you use Autodetect Format during binding the MULTI-Module will choose DSMX 11ms and Channels 1-7 (change channels to 1-9 if you wish to assign switch above channel 7).
In order to use the manuals diagram of both sticks 'Down-Inside' to set a SAFE Select Switch Designation, you must have Throttle and Elevator channels set to Normal direction but the Aileron and Rudder set to Reverse direction.
If setting up a new model with all channels set to Normal you can hold both sticks 'Down-Outside' to assign the switch with 5x flips. This has been tested on a Mode 2 radio.
Servo refresh rate is 22ms unless 11ms is selected. The option to select the refresh rate when binding will be available in OpenTX 2.3.10+.
Throttle Kill is available on CH14 for models which need it (X-Vert, Blade 230S, etc)
If CH14 is between -100% and -50% the throttle output will be forced to the CH14 value minus 50:
CH14 is configured with a weight of -80%
When the switch is off, CH14 is at 0%
When the switch is on, the MULTI-Module sends a value of -130% on the throttle channel:
DSM2, resolution 1024, servo refresh rate can only be 22ms.
Note: 'DSM2 1F' was previously labelled as 'DSM 2 22ms'.
DSM2, resolution 2048, servo refresh rate can be 22ms or 11ms. All servo outputs will be 22ms when more than seven channels are configured.
Note: 'DSM2 2F' was previously labelled as 'DSM 2 11ms'.
DSMX, resolution 2048, servo refresh rate can only be 22ms.
Note: 'DSMX 1F' was previously labelled as 'DSM X 22ms'.
DSMX, resolution 2048, refresh rate 22ms or 11ms. All servo outputs will be 22ms when more than seven channels are configured.
Note: 'DSMX 2F' was previously labelled as 'DSM X 11ms'.
The Auto sub-protocol enables the radio to negotiate the correct settings for the receiver. Auto-negotiation is supported on OpenTX, erSkyTx, and er9x.
In OpenTX, Auto can be enabled by checking the Autodetect format box or selecting the Auto sub-protocol.
You must have telemetry enabled and working, and on erSkyTx you need to set the telemetry Usr proto to DSMx.