ICD-001 Commands
Introduction
Commands are messages sent from the external, 3rd party system to the Witness software. These enable external applications to request data or to control specific actions. The protocol and message format are exactly the same as outgoing messages. The same applies to the handshaking, there is no implicit security at the protocol level, so once connected the clients can starting sending correctly formatted messages to the Witness server.
The list of available commands exposes only a limited set of actions for 3rd party system, but additional functionality can be exposed as required. For further information please contact Navtech Radar Support.
Command Summary
The following section outlines a summary of all currently available commands. New commands will become available as required. Due to the modular nature of Witness and the flexible underlying communication framework, additional functions can be exposed with relative ease. We strongly recommend that all clients connected to the Witness software send a heartbeat, this is referred to as the Subscriber Heartbeat. This is explained below.
Contents
Subscriber Heartbeat
A subscriber heartbeat is used to indicate that a TCP or UDP client is still connected to the server. The Witness software will monitor all the incoming heartbeats from subscribers and as long as at least one client is connected Witness will consider the server connection to be active.
If the ICD-001 protocol is enabled then Witness will expect at least one client to be connected. In the event that no heartbeats are received then Witness will raise an alarm to indicate that no subscribers are connected.
The default behaviour is for the Witness server to raise an alarm if a client does not send heartbeats however this is configurable if the client does not want to send heartbeats. Where possible we recommend that clients send heartbeats in order to force connections to fail where connectivity has been lost.
A heartbeat is an empty message. Please refer to ICD-001 Communication and ICD-001 Heartbeat Report for information concerning the message header and structure. The same message structure is used for heartbeats originating from Witness.
Related Information
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ICD-001 Track Filter Command (Witness 4.0)
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ICD-001 Acknowledge Alarm Command (Witness 4.0)
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ICD-001 Request Status Command (Witness 4.0)
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ICD-001 Detection Command (Witness 4.0)
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ICD-001 Update Entity Command (Witness 4.0)
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ICD-001 System Profile Command (Witness 4.0)
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ICD-001 External Trigger Command (Witness 4.0)
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ICD-001 Command Reply (Witness 4.0)
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ICD-001 Camera Command (Witness 4.0)
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ICD-001 Track Command (Witness 4.0)