ComBlock COM-1826 Manuale - Pagina 16

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The output format is as follows:

- fixed-length preamble consisting of (in the order

of transmission)

- 2-byte length of payload data (excluding

preamble). In the range 1 to 1024 bytes.

- 2-byte frame counter, modulo 2

- 4-byte currently undefined

- 8-byte timestamp (last timestamp read from the

SDDS input frames, latched at the first demodulated

byte in the transmit frame).

The output frames are sent when one of two trigger

conditions is met:

- at least 1024 demodulated data bytes are waiting

in the transmit queue, or

- at least 0.5second has elapsed since the last output

frame and at least one demodulated data byte is

waiting in the transmit queue.

The payload data size is thus variable in the range 1

through 1024 bytes.

Bytes are packed MSb first. Only full bytes are

transmitted (no partially filled bytes).

Modulator

The built-in modulator includes the FEC encoding

and DSSS baseband modulation functions. The

modulator output can be directed to the internal

demodulator when the loopback control is enabled.

Depending on the ordering option, the modulator

output can also be directed to analog baseband or

RF.

Load Software Updates

From time to time, ComBlock software updates are

released.

To manually update the software, highlight the

ComBlock and click on the Swiss army knife

button.

The receiver can store multiple personalities. The

list of personalities stored within the ComBlock

Flash memory will be shown upon clicking on the

Swiss army knife button.

The default personality loaded at power up or after

a reboot is identified by a 'D' in the Default

column. Any unprotected personality can be

updated while the Default personality is running.

Select the personality index and click on the

"Add/Modify" button.