Micron Radio Control : Tx20v2 User Information

Tx20v2 is a hand-held wireless transmitter intended to control one model railway locomotive engine. It has a large knob for forward/reverse throttle control plus three push buttons and one 3-way toggle switch for control of auxiliary circuits such as lighting, sound card triggers and couplers.

Tx20v2 can be used for Micron and Deltang receiver programming using the toggle switch to step through programming levels. Programming details for each receiver may be accessed from the web page for the receiver.

Technology

Tx20v2 uses the 2.4GHz band which requires no frequency channel control and is very resilient against interference. All radio frequency components are contained on the internal Tx2 module. There are no user adjustable parts on this module and it should not be modified.
Tx20v2 is compatible with all DSM2 receivers; this includes all Deltang receivers.
Any number of receivers can be bound to your Tx20v2 but only one should normally be switched on at a time to operate them independently.
Range is suitable for indoors and small outdoor sites; the outdoor free-air range to a Deltang receiver is at least 50m. Range indoors is affected by building construction materials, furniture, people and receiver installation.
The throttle control knob and bind push button action are transmitted as separate R/C 'channels' which must match the receiver configuration:

Tx20v2 uses a PP3 9V battery, preferably Alkaline or NiMH / Lithium rechargeable. The maximum working voltage of the internal electronics module is 10V and there is a protection diode wired in series with the battery lead. This allows the battery voltage to be up to 10.7V. If the battery voltage is above this value, the internal regulator will shut down and the transmitter will not operate.

Tx20v2 has a 2-way latching toggle switch for power and and adjacent LED indicator. The LED lights continuously when the transmitter is on and flashes when Tx20v2 is in bind mode (see below). It is best to switch the transmitter on before the receiver. If a receiver is switched on with Tx20v2 off, it is likely to enter bind mode with rapid flashing of the LED on the receiver board. If you did not intend to bind, switch the receiver off, then switch Tx20v2 on followed by the receiver.

Tx20v2 is available with a centre-off or low-off throttle control. The throttle type is actually implemented in the receiver, transmitter difference are the front-panel label and whether there is a centre-click on the throttle.

The 3-way toggle switch is used to select forward/reverse with receivers that have 'low off', full-range motor control. it can be used to control lights instead of direction with receivers that have 'centre off' motor control. The switch controls R/C channel 3 and the transmitted values are:

Note: holding the bind button for longer than 20 seconds will result in strange things happening (see Calibration).

If a receiver has not previously been bound, it has to be 'paired' with the transmitter. Binding is only required once per receiver.

During normal transmitter opertion, the bind button controls R/C channel 5. The transmitted value is high when the button is up and low when pressed.

The two auxiliary function push buttons F1 and F2 may be used to control lighting, couplers, sound cards, etc. They control R/C channels 2 and 4. The transmitted value is mid when the button is up and low when pressed.

Tx20v2 can be used to program Micron and Deltang receivers. You need to refer to the receiver's programming instructions for details of the available functions and the programming sequence to modify the functions.

All of these receivers have a common method of entering programming mode and modifying the programme data. Programming mode is entered by setting the transmitter channel 2 and channel 4 to maximum low or maximum high before applying power to the receiver and then setting both channels back to the middle. Program data is modified by pulsing channel 3 low and stored by pulsing channel 3 high. This corresponds to the following controls on Tx20v2.

Enter programming mode:	Turn on Tx20v2 and hold down F1 and F2. Apply power to the rx and the LED will start rapid flashing. Release F1 and F2. The Rx LED will now show a 1-flash – this is a repeated single short flash followed by a longer pause. This first flash pattern is called the 'Menu' in the programming instructions.
Modify programme sequence value:	Pulse the toggle switch down. The Rx LED will briefly show rapid flashing and then the next flash in the sequence – i.e. if it was showing 1-flash it will now show 2-flash. The flash sequence returns to 1-flash when advancing beyond the last value in a sequence. The number of the last value depends on the particular sequence being programmed.
Store programme sequence value:	Pulse the toggle switch up. The Rx LED will briefly show rapid flashing and then show the currently programmed flash pattern for the next in the sequence.

For example, to set the ESC output (the first if the receiver has multiple ESC) to respond to full range throttle on channel 1 and direction control on channel 3, the programme sequence is 1,1,2,1,3:

All ready-to-use transmitters are calibrated as the final manufacturing step. This sets the throttle control centre position and normally only needs to be done once. If you suspect that the throttle control is not operating correctly or you have replaced any of the internal components (e.g. throttle potentiometer), your transmitter may need calibration.

If the bind button has been inadvertently held down for longer than 20 seconds, the previously stored calibration data will have been overwritten and you could find that the throttle control behaves strangely.