Current version of the SDK for 64 bit USB instruments

SDK for USB Instruments & Gauges (544kb)
This download contains the latest version of our SDK. This Software Development Kit is specifically designed to work with our 64 bit USB Gauges and Instruments. Example source codes and manual are included in this SDK.

Older version of the SDK for 32 bit and CCU instruments (not supported anymore)

TRC/SimKits products come with controller boards which connect to your PC running Flight Simulator Software. The CCU (controlling the gauges) and the RSC (controlling the radio modules) connect to your PC via USB. TRC provides you with interface drivers to run on your PC to connect with Microsoft FS2002/2004 (for FS2004 a license for FSUIPC from Pete Dowson is needed). For other flight simulator software packages which are on the market, TRC provides so-called SDKs (Software Development Kits). These SDKs provide easy interfacing for programmers to write their own interface program for any flight simulator not supported by TRC or for other purposes.

Although that you need to be a programmer, the SDK supplies example programs in Microsoft Visual C++, Borland C++ Builder, Microsoft Visual Basic and Borland Delphi, to make it easier to understand how the SDK works. As the SDK software is distributed free of charge, we will not give support on how to write your application software, since programming knowledge is expected and it is up to you how you use the SDK. However, if you find a bug in the SDK, full software support will be given. A special section in the forum will be opened for discussions on the SDK. Tutorials and a sample program will be supplied for every programming language.

SDK for controlling SimKits gauges. version 2.94
With the use of the SDK, you can drive the SimKits devices from your own software via simple function calls. It is possible to read data from, and write data to SimKits devices via the CCU. Since the communication between the SimKits driver software (controlling the CCU board) and the SDK software is done via TCP/IP, you can either drive the devices from another computer over a network, or from the same computer where the CCU is installed.

Using the SDK, all I/O lines of the Central Control Unit are accessible as devices (an Airspeed Indicator is a Device, like a Switch is a Device). So now you can even control inputs as there are for the Yoke, Rudder Pedals, Digital Clock, Switches, Circuit Breakers, etc. The SDK does even allow you to write or read to or from individual I/O pins of some connectors on the CCU.

Now you can write your own application software for:
– Interfacing to any other Flight Simulator Software than FS2002/4
– Direct control of the gauges from self written IFR Training software
– Fun Applications

Devices are controlled very easy. For example, to position the Altimeter on an altitude of 12.000 feet, you simply send the value “ALTIMETER 12000”. Or to set the Airspeed indicator to 98.5 Knots, you use the value “AIRSPEED 98.5”.

The SDK includes sample source code for all supported programming languages.

The SDK supports the following programming languages/environment:

  1. Microsoft Visual C++
  2. Borland C++ Builder
  3. Microsoft Visual Basic
  4. Borland Delphi

– As many users have now the TRC Yoke – which has a realistic travel of over 18 cm. in and outwards and a realistic roll of 180 degrees – the sensitivity of the Yoke was too slow. When moving the Yoke now with this new release, the reaction of the aircraft is more in accordance with reality.
– The second improvement is for the Trimwheel, which is now disabled in all vertical NAV modes when using the auto pilot. This fix has the following reason: Microsoft Flight Simulator is changing the physical setting of the Trim Wheel when controlling the aircraft via the Autopilot. Since the hardware trim wheel position cannot be changed by MS FS, the actual (hardware) trim wheel position conflicted with the MS FS trim wheel position in software. This has now been fixed. Note: when you do an approach on the Autopilot, you have to take care that the trim wheel is in a neutral position when taking over the aircraft on short final from the Autopilot. When you switch off the Autopilot, the trim wheel will be enabled immediately. A wrong position of the trim wheel can cause unexpected decrease or increase of the aircraft causing problems on short final!
– The third improvement is on the VOR1 use. Under certain circumstances the VOR1 could indicate wrong values. This has been corrected.
– The altimeter is movement is improved, and acts more realistic.

In version 2.95 the following improvements/additions have been made:
– An “error 2” is returned if a value is requested from an instrument which is not installed in the calibration tool.
– A new variable “set_reply” keyword added, this variable is used to indicate if a “ok” reply should be returned after submitting a value to a varaible:
0 = no reply, 1 (default) = reply
– A TCP/IP error will not open an error messagebox anymore

Download SDK Manual in PDF (210Kbyte)
Download SDK 2.95 (4.6Mbyte)

SDK for controlling the RSC372 Radio Stack modules
The TRC Radio Stack is an extreme realistic set of avionics, controlled by an electronics interface board called RSC and software drivers, developed by TRC Development b.v.
There are drivers available which connect directly with Microsoft Flight Simulator FS2002 or FS2004 if you don’t want to program yourselves (it is necessary to obtain a license for FSUIPC from Pete Dowson when using FS2004). The SDK includes sample source code for all supported programming languages.

Because of many requests from cockpit builders with programming skills, TRC Development has produced a so-called Radio Stack SDK. The Radio Stack SDK enables you to drive the Radio Stack devices from your own (Flight Simulator) software. Basically, with the use of the Radio Stack SDK, there is no limit to use the Radio Stack Devices from any type of software written by yourself. With the use of the Radio Stack SDK, you can read and write values directly to and from the Radio Stack Devices.

The Radio Stack SDK requires programming knowledge on one the following programming languages:

  1. Microsoft Visual C++
  2. Borland C++ Builder
  3. Microsoft Visual Basic
  4. Borland Delphi

Latest version of the Radio Stack SDK, version 1.6b2
– TCP/IP errors will only generate a message in the toolbar and not a MessageDialog.
– SDK accepts both . and , as decimal separator.
– added feature to allow programming of the VFR code.
– ADF range changed to 200-1799
– Added ADF countdown timer
– Added ADF Fly Timer
– New variables for Autopilot

New SDK variables:
ground – Ground indicator (0=flying / 1=ground)
adf_adf – ADF mode (0=ant / 1=adf)
adf_bfo – BFO mode (0=off / 1=bfo)

New SDK Variables added in version 1.6b2:
autopilot_arm – 0 = arm off / 1= arm on
autopilot_altmode – 0 = alt mode disabled / 1 = alt mode enabled
autopilot_vsmode – 0 = vs mode disabled / 1 = vs mode enabled
These variables are read only.

Solved in previous versions:

LCD Display routines are improved. The radio stack component which is updated because the user turns the knob is updated before other displays are updated. Radio Stack components can be enabled/disabled with checkboxes in the main screen of the application.
Support for rotary encoders panel added: VOR1OBS, VOR2OBS, AltiPres, Heading HDG, Heading Drift, ADFHDG.

Comm 1/2
Channels support added, channels can be selected and programmed (32 channels).
Active/CDI mode added with VOR function.
Volume read support for comm and nav.

Audio volume read support added.
The Inner, Middle and Outer Marker illumination is added on the Audio Panel.
The COM1/COM2 selection is now controlled in the Audio Panel with the MIC selector.

Vertical speed / Altimeter height values can be negative on display.
There was an error when using the Autopilot inner knob. This is fixed and will change the altitude now by the correct value of 100 feet per click. (This was 20ft.)

Elapsed Time function added.
In MS FS, the ADF has the possibility to set fractions. Originally, the Bendix King Radio Stack has no decimal point and searches eventual frequencies with a value behind the decimal point automatically. This was not functioning properly in the previous Radio Stack software. This has been fixed.
ADF volume read support added.


When using the Transponder, the “R” signal is now blinking when enabled.
All the modes can now be selected in transponder (ALT/ON/TST/SBY/OFF)

Minutes away from beacon is now also calculated displayed when nautical miles value is known.

Download Radio Stack Controller SDK 1.6b2 (3.1Mbyte)
Download Radio Stack Controller SDK Manual 1.1 in PDF (150Kbyte)