Setting up the ST90 system for synchronized operation

If you want to use the ST90 system 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.

This procedure assumes that:

  • The vessel is berthed or at sea.

  • You have an RS2-232 interface port on your computer that allows you to use the CTS/RTS connections.

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.

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.

  • One of the acoustic systems is set up as "master", and controls the transmissions on the other systems.

The ST90 system offers functionality for remote transmit synchronization. It can be set up to operate in either Master or Slave mode.

Note:

When you work in the Installation dialog box, you must always select Apply to save the changes made on a page. You must do this before you continue working on a different page.

Procedure

  1. Connect the synchronization cable from the remote system to an available communication port on your computer.

    This is described in the Installation Manual.

  2. Turn on the ST90 system and set it to normal use.
  3. Open the Setup menu.
  4. On the Setup menu, select Installation.

    Observe that the Installation dialog box opens. This dialog box contains a number of pages selected from the menu on the left side.

  5. On the left side of the Installation dialog box, select Synchronization.
  6. Select Synchronization Mode.

    • Stand-alone

      This synchronization mode is used when the ST90 system is working by itself. Synchronization is turned off. It is the default setting. The ST90 system operates using the current settings for ping interval. The operation is independent of any trigger signals arriving at the synchronization port.

      The Synchronization Delay setting is not applicable when synchronization is switched off.

    • Master

      Master mode is used if the ST90 system shall operate as the controlling unit in a synchronized system. Any peripheral hydroacoustic system(s) are only permitted to transmit when enabled by the ST90 system. The ST90 system operates using the current settings for ping interval. It also sends trigger signals to the peripheral system(s).

      This mode is unavailable if you set Synchronization Port to Transceiver Auxiliary Port.

    • Slave

      The Slave mode is used if the ST90 system shall transmit only when permitted by a peripheral system. When the Slave mode is selected, the ST90 system will not transmit ("ping") unless an external trigger appears on the chosen synchronization port. The peripheral system may be any other hydroacoustic product (for example an echo sounder or sonar), or even a dedicated synchronization system.

  7. Select Synchronization Delay.

    This delay parameter is used differently depending on the chosen synchronization mode.

    • Stand-alone

      The Synchronization Delay setting is not applicable when synchronization is switched off.

    • Master

      In Master mode, the ST90 system waits for the delay time after the external trigger signal has been sent to the slaves before transmitting the ping. This is often referred to as a pre-trigger.

      Note:

      This delay will only work when the synchronization is set up using a serial port.

    • Slave

      In Slave mode, the ST90 system waits for the delay time after the external trigger signal has arrived before transmitting the ping. This is often referred to as a post-trigger.

  8. From the list of ports available, select Synchronization Port.

    This is the interface port currently used to transmit or receive synchronization signals. It must be an RS-232 serial port. Since the synchronization function only uses the Request To Send (RTS) and Clear To Send (CTS) signals on a serial port, you may be able to use a port that is already assigned other interface purposes. For the same reason, you do not need to define any baud rate.

  9. At the bottom of the page, select Apply to save your settings.
  10. Continue your work in the Installation dialog box, or select OK to close it.