Message Format - quercus SmartLoop TS Programming Manual

QuercusVL Programming Manual
information or to request an action (activate an output, reboot the unit, etc.). All requests will
be answered immediately by the unit with a response message with the information requested,
an ACK if the message did not expect a response, or a NAK if the message could not be
properly received, interpreted, or completed.
Please note that between the reception of a request and its response, an event can occur in
the system, so that the first message to arrive after a request has been made might not be the
response to the request.
Example of requests and their responses:

4.1. Message format

Messages will always have the same format; Bytes are ordered in all fields with the "little-
endian" system:
1 4
Stx UnitId
Stx (1 byte): byte that marks the start of a frame (ASCII character 2).
●
Unit Id (4 bytes): identifier of the capture unit sending or receiving the message; a zero
●
means that this field has to be ignored.
Size (4 bytes): total size of the message in bytes.
●
Quercus Technologies
126
Unit
Event
4 2 2
Size Type Version
Central System
4
Variable
Id
Message data
1 1
Bcc Etx