Setting up the alarm limits for system protection

Safe operation of the ST90 system is made possible using multiple sensors that monitor the operation and the performance. Whenever a suspicious event takes place, a relevant message, warning or alarm is provided. Selected alarm limits may be adjusted to fit your operational requirements.

The System Protection page allows you to specify alarm limits for the hull unit and the transducer. Additional system protection features are also listed. These function are automatically monitored by the software in the ST90 system. You are not permitted to change the alarm limits.

If an alarm limit is exceeded a relevant message is issued by the ST90 system. At the same time, the relevant descriptive text is provided with a dark background.

Procedure

  1. Open the Setup menu.
  2. 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.

  3. On the left side of the Installation dialog box, select System Protection to open the page.
  4. Define the relevant parameters.
    Transducer
    Tx Inhibit Hull Unit Position

    If the transducer is activated when out of the water it may be damaged beyond repair. With the transducer fully retracted, no transmissions ("pings") take place. When you lower the transducer into the water, you can specify a vertical position for when the transmissions start. When the transducer is retracted, transmissions will stop when the transducer reaches the same position.

    Tx Inhibit Power

    The high voltage supplied to the transceiver boards is monitored. You are not permitted to change the alarm limits. If this voltage differs from the defined tolerances, alarm message AKH11 will be initiated: Transmission is inhibited due to a high voltage in the power supply.

    Tx Inhibit Operation Mode

    This feature activates the system protection to make sure that the ST90 system does not transmit ("ping") when you have chosen Replay or Inactive mode.

    Hull Unit

    You must specify a maximum speed for the vessel. This speed can match the hull unit specification, or you can choose a lower speed for increased safety.

    Note:

    We strongly recommend that you do not specify a higher speed than the hull unit is designed for.

    If the speed limit is exceeded a message is issued by the ST90 system.

    The ST90 system can be provided with one of the following hull units:

    Hull UnitLowering depth (m)Transducer cable (m)Maximum speed (knots)
    ST921.24.6 16
    7
    ST931.64.6 16
    7
    ST942.14.611
    7
    The same transducer is used on all hull unit types.
    If a Hull Unit Controller is supplied with the system, the Motor Control Unit cabinet is used as a junction box.
    Screen Recording

    We recommend that you do not make any changes to these settings.

    Recording

    We recommend that you do not make any changes to these settings.

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