Wednesday 1 February 2012

Multiplex Profi Tx announced

Multiplex fans will be excited by the recent announcement of their new flagship radio, the Profi. The new radio is being touted as the natural successor to the legendary Profi mc4000, and will be offered with a choice of 9, 12 and 16 channels. Each version optionally comes with the appropriate DR Pro telemetry receiver.

It certainly looks an interesting system, and will undoubtedly provide an upgrade path for users of the Royal Evo and Royal Pro. However, users of the old Profi 4000 are a sceptical bunch, and they will be looking for reassurance that the new Profi is as flexible as the 4000 which is widely regarded as the most capable (if rather tricky to program) system for glider flyers.

In the absence of a manual (presumably both the firmware and documentation are not yet finalised), all we have to go on is the (a) officially published specs and (b) the pre-production programming screens shown in various videos. However, these do provide some useful clues, so let's dive in.

Multiplex Profi

Multiplex Profi - features

Let's start with the more interesting new features:
  • Integrated antenna (improved radiation pattern, no more broken antennas)
  • Hinged, wide format 5.8" LCD panel
  • Vibration alarm
  • LiFePO4 battery (25 hours duration)
  • Option of mains or 12V charger (not supplied)
  • Charger connects to tx via USB lead (supplied).
  • Earphone socket for telemetry
  • Warning monitor panel for telemetry
  • 200 model memories via SD card
  • Foldaway neckstrap arms
  • Optional transmitter tray

Firmware ancestry

Development of the Profi has been an open secret for months, and there has been inevitable speculation about its DNA. Would Multiplex develop new firmware from scratch? Would they port the 4000 functionality on to new firmware? Or would they base the code on the Royal Pro?

A clue lies in the quick access keys for the menus - these have the same layout and legends as those on the Royal Pro. The similarity extends further to the menus and programming screens.

The likely conclusion is that the programming is similar if not actually based on the RP. Existing mc4000 owners hoping for a straight port may be disappointed. Realistically, though, this was never going to happen. The question remains as to how far Multiplex have been able to extend the functionality into mc4000 territory.

Spot the similarity.  Profi (above), Royal Pro (below).


One area where the Royal Pro is weak is in the programming of 3-position switches. Those on the new Profi are said to be 'fully programmable'. Hopefully this means that each of the three positions can be programmed as independent virtual 2-position switches, as on the mc4000.

As I write, there is no word on the provision of analogue and logical switches.


The mixer architecture of any radio is the key to its flexibility, and this is the key area where Multiplex compromised with the Royal Evo, and subsequently the Royal Pro. Not only do these radios lack server side mixers and multimix of the 4000, they adopted the much-disliked 'global/shared' mixer scheme. At least the new Profi appears to have reverted to the 'private' mixer scheme.

As regards the other specs:

"Five mixers per model, 8 mixer inputs per mixer...". This sounds more "Royal Pro" than "4000".

"... curve mixer..." implies that you can define a your own mixer curve rather than being limited to just the pre-defined curve templates provided with the Royal Pro. It's not clear if this is a generic feature applicable to all mixers or if it's a special mixer in its own right.

Battery technology

Some interesting and innovative (for RC) developments here, centering around the single-cell 3.3V 4000 mAh LiFePO4 battery. Comprehensive battery management is provided (pre-production screen shots show Cycle Count, Time to Empty, Charge and Capacity). With just a single cell, no balancer is necessary, so the charger can be kept very simple. No battery charger is supplied, presumably because various charger options are available.

For info on LiFePO4 chemistry, see Wikipedia.


Multiplex have finally dispensed with the multifunction DIN socket. In it's place are a mini USB and a full size USB socket. These are used for battery charging and PC interfacing.

There is nothing in the specs about converting memories from the mc4000 to the new Profi.


With an earphone socket, a 'warning panel', and a dedicated 'vario' setup screen, the Profi hints at greater integration of telemetry. The telemetry display now includes a description of the sensor data.

mc4000 influences

There are a few touches taken directly from the mc4000, such as easy access to the interior, retractable carrying handle, and the front-facia sliders with dummy 'placeholders'... well it's nice to see the new kid taking some lessons from the old master!

Reactions from mc4000 users

As I write this section on 9th Feb 2012, there have been some concerned comments on the RCMF forum, mainly from mc4000 users seeking reassurance that the new Profi will provide a similar level of functionally compared with the old mc4000.

The key to the mc4000's flexibility was (a) servo-side curves and (b) multimixes (user defined mixer 'black boxes'), and doubts have been expressed as to whether the Multiplex engineers have matched this flexibility in the new radio. Certainly there is nothing in the spec both published and unofficial to suggest that they have. The limit of five mixers per model has also been commented on (my current F3F program uses eleven mixers).


Multiplex RC
Multiplex "New Items" 2012 (pdf)
YouTube intro by Gordon Upton
Official MPX vid of Nuremberg 
LiFePO4 batteries (Wikipedia)
RCMF Forum (14 Feb - thread appears to have been removed by the mod)


Geoff said...

Time to do whatever is required to get your hands on one, and tell us what the software is REALLY like :)

Trev said...

Any update on availability or features. Am quite interested in this release.

RC Soar said...

Nothing more is known as far as I'm aware, though it's due for launch this year.

Trev said...

Thank you for the reply. Also, for those interested in this check out Weatronic. Looks like they are progressing with their new TX. That one is also very interesting!

RC Soar said...

Thanks for the heads up re Weatronic - looks interesting. With all these systems using their own proprietary protocols, long term support is going to be a crucial factor. Sometimes I wish for the old days when any tx worked with any rx, regardless of brand.