Simrad SC90, Installation Manual

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"Event" message. The message is processed by the SC90 software, and it will (if the
previous ping has been finished) start the ping sequence.
As an acknowledge to the synchronisation trigger, the SC90 sets the Ready To Send
(RTS) signal to a logic "low" before transmitting. This indicates that the SC90 is "busy".
Once the transmission and reception sequence ends, the SC90 sets the Ready To Send
(RTS) signal to logic "high" to indicate that it is ready for the next ping.
Master mode
When the SC90 is "Master" in a system, the synchronization can either take place in Free
running mode, or in Wait for slave mode.
• Synchronization in Free running mode
When in Free running mode, the SC90 will ping as fast as possible, setting its Ready
to Send (RTS) signal to a logic "high" at start of each ping, and back to logic "low”
at the end of the ping. The "Slave" system is triggered the when the Ready to Send
(RTS) signal goes from "low" to "high".
• Synchronization in Wait for slave mode
When in Wait for slave mode, the SC90 will wait for a logic "high" Clear to Send
(CTS) signal from the "Slave" system before it starts a new ping sequence. This is the
"ready to ping" acknowledge from the "Slave" system.
Note
If you use the SC90 as "Master" to control two "Slave" systems, you must connect a
single cable (plus ground) from the Ready to Send (RTS) output on the Master system to
the Clear to Send (CTS) input on both "Slave" systems. The return from the Ready to
Send (RTS) outputs on the "Slave" systems can not be connected.
Selecting synchronization port
If you wish to use the SC90 as a master or slave in a synchronized system, you must set
it up for such operation. To do this, you must select which communication port to use for
the synchronization interface, and you must select the requested synchronization mode.
Prerequisites
Neither tools nor instruments are required. The SC90 is turned on, and it is working
normally.
• For "slave" operation, a remote system (for example K-Sync ) must be available to
provide trigger pulses.
• For "master" operation, a remote system must be connected. This remote system
must be set up in "slave" mode.
The external system is connected to a serial communication port on the Processor Unit.
Cable layout and interconnections