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The exchanged messages have the following format (so called "Double DLE"):

where <DLE> is the "Data Link Escape" ASCII character (decimal 16), <STX> is the "Start of TeXt" ASCII character (decimal 2), <COMMAND> is a command string, <DATA> is the exchanged data (if any), <CHECKSUM> is the checksum byte and <ETX> is the "End of TeXt" ASCII byte (decimal 3). If a byte in the <DATA> block has the value of the <DLE> character it is repeated (ie transmitted as <DLE><DLE>), so that the starting and closing character combinations are unique.

Thus, on detection of a <DLE><STX> string, the receiving hardware prepares for the reception of a new message (being a command or the response to an issued command). On detection of a <DLE><DLE> string, only one <DLE> byte is entered in the buffer and on receiving a <DLE><ETX>, the message is closed. Processing of the received message starts immediately after its integrity has been checked. (The <CHECKSUM> byte equals to the simple sum of the message bytes).

As Quamatic nodes can be chained, they are addressed by their address byte. Thus, the <COMMAND> string to a node or a satellite in the network carries the node address byte and the command character. The <NUL> address byte (decimal 0) is reserved for broadcasting network-wide commands and messages. The following are typical commands implemented in most hardware:

• Status request. The addressed satelite or node is requested to provide its current status.
• "Who Are You" request. The addressed satelite or node is requested to provide its hardware identity, software version, processor speed etc.
• Configuration request. The addressed satelite or node is requested to provide its current configuration file.
• Progress request. The addressed satelite or node is requested to provide its current data.
• Data request. The addressed satelite or node is requested to provide its stored data.
• Accumulated totals request. The addressed satelite or node is requested to provide its accumulated totals.
• "Go" command. The addressed satelite or node is commanded to start automatic operation.
• "Quiet" command. The addressed satelite or node is commanded to stop automatic operation.
• Zero totals command. The addressed satelite or node is commanded to zero or initialize its accumulated totals.
• Set time command. The addressed satelite or node is commanded to set its clocks to the provided timestamp.
• Load configuration command. The addressed satelite or node is commanded to load the provided configuration file or data.
• Data command. The addressed satelite or node is commanded to load the provided data.

All Quamatic hardware, unless specifically stated, handles MSB (Most Significant Byte) first data.