Variable

When selecting the outgoing messages, the indicated varible is sent trough the serial port according to the structure defined in the menu shown in the following figure.
fig.080-variable

Variable

  • Bit Lenght: it is possible to compress the variable selected by choosing the option Compress, this allows the system not to fill the storage. Uncompressed uses original values, they are Float (32 bits).
    • Compress (Decimals): sets the number of decimals to use and the limits of the variable (Min-Max), any variable out of the limits will be set to these values. For instance, in the image below the AGL can have a value between -10 and 1000.0 with 2 decimals i.e, if the AGL has a value of 500.43453, it will be compress to 500.43.
    • Compress (Bits signed): sets the number the bits. User has to configure the option Input/Output.
    • Compress (Bits unsigned):sets the number the bits. User has to configure the option Input/Output.
  • Input/Output: these values are used to apply a factor and/or offset after the transformation from binary to decimal value. For instance, if the variable considered is unsigned of 3 bits it can go from 0 to 7 (in decimal), but if there is a conversion expressed as: Input (Min:0 – Max: 0.1) and Output (Min:0 – Max: 1). The variable value is divided by ten after the transformation, so it will vary between 0 and 0.7 .

Checksum

Sometimes, control codes are needed for preventing random errors in transmission, where bits frame is operated and the result is sent to the receiver to check it. To do so the CheckSum option is used.

fig.081-checksum

CheckSum

  • Back From-Back To: It sets the stage where CRC will be applied
  • Endiannes: (Explained above)
  • Type: User can choose the type of CRC that will be applied.

Matcher

The matcher is the field used to send a constant value through the serial port. The configuration of this field is done by selecting its length (number of bits) and the value that will contain.

fig.082-matcher

Matcher

  • Nº Bits: number of bits in which the matcher is performed.
  • Value: just accept and send this decimal value among all possible values according to number of bits set.
  • Mask: this value (Decimal) is converted into binary. This option lets accept this binary value and others which match the condition shown in the example:

Mask = 5 (Decimal Value)

To binary is 0000 0101

This Mask accepts all the values 0000 0x0x, can accept 0, 1, 4 being that:

0=0000 0000

1=0000 0001

4=0000 0100

and of course 5=0000 0101

Skip

Finally, the skip option is used to skip a certain number of bits within the message.

fig.083-skip

Skip

Skip Nº Bits: skip the number of bits defined