Simrad SN90, Operator'S Manual

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Master mode
When the SN90 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 SN90 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 SN90 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 SN90 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.
Related topics
Setting up the SN90 in a synchronized system, page 148
Selecting synchronization port
If you want to use the SN90 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 SN90 system is turned on and operates
normally.
• For "slave" operation, a remote system (for example K-Sync or Simrad TU40 ) must
be available to provide trigger pulses.
• For "master" operation, a remote hydroacoustic system (sonar, echo sounder) is
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.
Context
Whenever more than one hydroacoustic system is installed on a vessel, interference may
occur. To avoid interference, you have these options:
• The systems are all connected to a common synchronization system.
Operating procedures