RINEX 3.02

How to integrate the INS with an external Air Data Computer (ADC)

Purpose: Learn how to connect the INS to an external ADC
Last Updated: January 2025

The article describes integrating the Inertial Navigation System (INS) with an external Air Data Computer (ADC). For the ADC with the INS integration, the COM1 serial port of the ADC should be connected to the COM4 serial port of the INS using the serial-to-serial cable with RS-232 interface, and the COM1 serial port of the INS should be connected to the host computer. The INS and ADC must have the same COM-port baud rate for proper communication and data transfer between the devices. We recommend using a 460800 bps baud rate and RS-232 serial interface for connection.

However, both devices must be separately preconfigured before integration. Adjustments can be made using GUI software or by command. The article contains instructions for both methods: using GUI and commands for ADC and then appropriate methods for INS. 

 

The ADC configuration using the ADC GUI
 

Connect the ADC to the computer and power it on. Choose the serial port number to which the device’s main COM1 port is connected and set the baud rate manually, or click the “Auto” button to automatically detect the unit’s baud rate in the “Test options” menu of the ADC GUI. The checkbox “Allow auto start” should be enabled. The adjustments of the ADC in the “Test options” menu of the ADC GUI should be as in Fig.1. Click on “Aiding data” output data format, and a pop-up window will appear (Fig.2), where it is necessary to choose Pressures and press the OK button twice. 

 

ADC adjustment
Fig.1 ADC configuration in the "Test options" menu
ADC adjustment
Fig.2 ADC configuration in the "Test options" menu

Use the “Read parameters” item under the Parameters menu to read the parameters from the connected device memory. An information window “Parameters were successfully read” will appear. Open the “Devices options” menu of the ADC GUI, set COM Port bps to 460800, set Data rate to 50Hz and Auto start to Aiding data. The adjustments of the ADC in the “Devices options” menu of the ADC GUI should be as in Figure 3. Press the OK button and use the “Write parameters” item under the Parameters menu to apply changes. An information window “Parameters were successfully written” will appear.

ADC adjustment
Fig.3 ADC configuration in the "Devices options" menu
 
The INS configuration using the INS GUI
 

Connect the INS to the computer and power it on. Choose the serial port number to which the device’s main COM1 port is connected and set the baud rate manually, or click the “Auto” button to automatically detect the unit’s baud rate in the “Test options” menu of the INS GUI. Use the “Read parameters” item under the Parameters menu to read the parameters from the connected device memory. An information window “Parameters were successfully read” will appear. Open the “Devices options” menu of the INS GUI and set COM Port bps to 460800 in the “IMU” tab(Fig.4), the next step is to set Pressure sensors to an External ADC and for Air speed source – Diff. pressure sensor in the “Air data” tab(Fig.5), and the last step in the “Devices options” menu is to configure the COM4 serial port of the INS to accept aiding data from the ADC. For this, open the “CAN/COM4” tab and set COM Port 4 to Aiding Data input and Port bps to 460800 (Fig.6).

 

INS adjustment
Fig.4 INS configuration in the "IMU" tab of the "Devices options" menu
INS adjustment
Fig.5 INS configuration in the "Air data" tab of the "Devices options" menu
INS adjustment
Fig.6 INS configuration in the "CAN/COM4" tab of the "Devices options" menu
After completing the INS settings within the  GUI, use the “Write parameters” item under the Parameters menu to apply changes. An information window “Parameters were successfully written” will appear (Fig.7). 
How to review and change parameters of the device using updated GUI
Fig.7 "Parameters were successfully written"
The ADC configuration by commands
 

The following process demonstrates the required sequence of commands to configure the ADC so that the COM1 serial port outputs data at a baud rate of 460800 bps and 50 Hz data rate, turns on the AutoStart for output pressures aiding data, and saves this setting to the device’s nonvolatile memory. Connect the ADC to the computer and power it on. Open any serial port terminal, choose the serial port number to which the device’s main COM1 port is connected, and set the baud rate manually. 

The first command that we recommend sending is Stop, which has a constant structure so that the ADC switches to idle mode and is ready to accept commands from the host computer:

AA 55 00 00 07 00 FE 05 01

AA 55 – Header, 00 – Message type, 00 – Message identifier, 07 00 – Message length, FE – Stop command code, 05 01 – Checksum.

 The second command is LoadADCpar_RAM to output data at a baud rate of 460800 bps through the COM1 port:

AA 55 00 00 09 00 B0 01 09 C3 00

AA 55 – Header, 00 – Message type, 00 – Message identifier, 09 00 – Message length, B0 – Code for LoadADCpar_RAM command, 01 – Parameter code, 09 – Parameter value 460800, C3 00 – Checksum.

The response to the LoadADCpar_RAM command should be as follows: 

AA 55 01 B0 09 00 00 00 00 BA 00

AA 55 – Header, 01 – Message type, B0- Message identifier, 09 00 – Message length, 00 – Data list error, 00 00 – Reserved, BA 00 – Checksum. If all bit values are 0 for the Data list error, there is no error in the parameter code, payload, and parameter values. A value of 1 for any of the bits indicates the errors shown in Table 5.2.3 of the ADC ICD.

The third command is LoadADCpar_RAM to output data with a 50 Hz data rate through the COM1 port:

AA 55 00 00 0B 00 B0 02 32 00 01 F0 00

AA 55 – Header, 00 – Message type, 00 – Message identifier, 0B 00 – Message length, B0 – Code for LoadADCpar_RAM command, 02 – Parameter code, 32 00 – Parameter value for 50 Hz, 01 – Reserved, always 01,  F0 00 – Checksum.

The response to the LoadADCpar_RAM command should be as follows: 

AA 55 01 B0 09 00 00 00 00 BA 00

AA 55 – Header, 01 – Message type, B0- Message identifier, 09 00 – Message length, 00 – Data list error, 00 00 – Reserved, BA 00 – Checksum. If all bit values are 0 for the Data list error, there is no error in the parameter code, payload, and parameter values. A value of 1 for any of the bits indicates the errors shown in Table 5.2.3 of the ADC ICD.

The fourth command is LoadADCpar_RAM to output static and dynamic pressures aiding data on AutoStart mode: 

AA 55 00 00 09 00 B0 07 7F 3F 01

 AA 55 – Header, 00 – Message type, 00 – Message identifier, 09 00 – Message length, B0 – Code for LoadADCpar_RAM command, 07 – AutoStart parameter code, 7F- Parameter value Pressures Aiding Data, 3F 01 – Checksum.

The response to the LoadADCpar_RAM command should be as follows: 

AA 55 01 B0 09 00 00 00 00 BA 00

AA 55 – Header, 01 – Message type, B0- Message identifier, 09 00 – Message length, 00 – Data list error, 00 00 – Reserved, BA 00 – Checksum. If all bit values are 0 for the Data list error, there is no error in the parameter code, payload, and parameter values. A value of 1 for any of the bits indicates the errors shown in Table 5.2.3 of the ADC ICD.

The last command is SaveADCpar_FLS, which has a constant structure. Save command would save all current device configurations from the RAM to nonvolatile memory:

AA 55 00 00 07 00 B2 B9 00

AA 55 – Header, 00 – Message type, 00 – Message identifier, 07 00 – Message length, B2 – SaveADCpar_FLS command code, B9 00 – Checksum. 

The response to the SaveADCpar_FLS command should be as follows:

AA 55 01 B2 08 00 B9 00 74 01 

AA 55 – Header, 01 – Message type, B2 – Message identifier, 08 00 – Message length, B9 00 –  Checksum of the SaveADCpar_FLS command, 74 01 – Checksum.

The INS configuration by commands

The following process demonstrates the required sequence of commands to configure the INS so that the COM1 serial port outputs data at a baud rate of 460800 bps, to set Pressure sensors to an External ADC and for Air speed source – Diff. pressure sensor, and configure the COM4 serial port of the INS to accept aiding data from the ADC. Open any serial port terminal, choose the serial port number to which the device’s main COM1 port is connected, and set the baud rate manually. 

The first command that we recommend sending is Stop, which has a constant structure so that the ADC switches to idle mode and is ready to accept commands from the host computer:

AA 55 00 00 07 00 FE 05 01

AA 55 – Header, 00 – Message type, 00 – Message identifier, 07 00 – Message length, FE – Stop command code, 05 01 – Checksum.

 The second command is LoadINSpar_RAM to output data at a baud rate of 460800 bps through the COM1 port:

AA 55 00 00 09 00 B0 01 09 C3 00

AA 55 – Header, 00 – Message type, 00 – Message identifier, 09 00 – Message length, B0 – Code for LoadINSpar_RAM command, 01 – Parameter code, 09 – Parameter value 460800, C3 00 – Checksum.

The response to the LoadINSpar_RAM command should be as follows: 

AA 55 01 B0 09 00 00 00 00 BA 00

AA 55 – Header, 01 – Message type, B0- Message identifier, 09 00 – Message length, 00 – Data list error, 00 00 – Reserved, BA 00 – Checksum. If all bit values are 0 for the Data list error, there is no error in the parameter code, payload, and parameter values. A value of 1 for any of the bits indicates the errors shown in Table 6.96 of the INS ICD.

The third command is LoadINSpar_RAM to set Pressure sensors to an External ADC

AA 55 00 00 09 00 B0 95 01 4F 01

 AA 55 – Header, 00 – Message type, 00 – Message identifier, 09 00 – Message length, B0 – Code for LoadINSpar_RAM command, 95 – , 01 – Parameter value Pressures Aiding Data, 4F 01 – Checksum.

The response to the LoadINSpar_RAM command should be as follows: 

AA 55 01 B0 09 00 00 00 00 BA 00

AA 55 – Header, 01 – Message type, B0- Message identifier, 09 00 – Message length, 00 – Data list error, 00 00 – Reserved, BA 00 – Checksum. If all bit values are 0 for the Data list error, there is no error in the parameter code, payload, and parameter values. A value of 1 for any of the bits indicates the errors shown in Table 6.96 of the INS ICD.

The fourth command is LoadINSpar_RAM to set the Air speed source to Diff. pressure sensor

AA 55 00 00 0A 00 B0 91 01 05 51 01

 AA 55 – Header, 00 – Message type, 00 – Message identifier, 0A 00 – Message length, B0 – Code for LoadINSpar_RAM command, 91 – AutoStart parameter code, 01- Parameter value Pressures Aiding Data,05- ,51 01 – Checksum.

The response to the LoadINSpar_RAM command should be as follows: 

AA 55 01 B0 09 00 00 00 00 BA 00

AA 55 – Header, 01 – Message type, B0- Message identifier, 09 00 – Message length, 00 – Data list error, 00 00 – Reserved, BA 00 – Checksum. If all bit values are 0 for the Data list error, there is no error in the parameter code, payload, and parameter values. A value of 1 for any of the bits indicates the errors shown in Table 6.96 of the INS ICD.

The fifth command is LoadINSpar_RAM to configure the COM4 serial port of the INS to accept aiding data from the ADC

AA 55 00 00 0B 00 B0 44 13 06 09 21 01

 AA 55 – Header, 00 – Message type, 00 – Message identifier, 0B 00 – Message length, B0 – Code for LoadINSpar_RAM command, 44 – AutoStart parameter code, 13- Parameter value Pressures Aiding Data, 06 – Parameter value Pressures Aiding Data, 09- Parameter value Pressures Aiding Data, 21 01 – Checksum.

The response to the LoadINSpar_RAM command should be as follows: 

AA 55 01 B0 09 00 00 00 00 BA 00

AA 55 – Header, 01 – Message type, B0- Message identifier, 09 00 – Message length, 00 – Data list error, 00 00 – Reserved, BA 00 – Checksum. If all bit values are 0 for the Data list error, there is no error in the parameter code, payload, and parameter values. A value of 1 for any of the bits indicates the errors shown in Table 6.96 of the INS ICD.

The last command is SaveINSpar_FLS, which has a constant structure. Save command would save all current device configurations from the RAM to nonvolatile memory:

AA 55 00 00 07 00 B2 B9 00

AA 55 – Header, 00 – Message type, 00 – Message identifier, 07 00 – Message length, B2 – SaveINSpar_FLS command code, B9 00 – Checksum.

The response to the SaveINSpar_FLS command should be as follows:

AA 55 01 B2 08 00 B9 00 74 01 

AA 55 – Header, 01 – Message type, B2 – Message identifier, 08 00 – Message length, B9 00 –  Checksum of the SaveINSpar_FLS command, BA 00 – Checksum.

The INS operation with an external ADC 

 

Once both devices are successfully preconfigured, the INS is ready to operate with an external ADC.

 

 
 

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