Continel protocol is an asynchronous communications protocol used in many Supervisory Control and Data Acquisition (SCADA) systems.
CONITEL Message blocks are composed of 31 bits plus a message synchronization “start bit” at the front of the first message block and an End of Message (EOM) bit at the end of each block. The protocol may be used either in a point-to-point or in a multi-drop configuration.
The protocol can be used in either half or full-duplex operation. Communications security is provided by a 5-bit Bose-Chaudhuri cyclic code which is included with each message block. All communications exchanges in CONITEL protocol are initiated by the host.
The remote cannot initiate any exchange with the host nor can the remote directly address or communicate with another remote. The remote will return a response to the host for all valid messages sent by the host and addressed to the remote.
The only exception to this is in broadcast (all station) messages which produce no response from any remote.
Also, all messages received by the remote are validated by checking the BCH code. If the BCH code is not valid, the remote will ignore the message; no action or response will be initiated.