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Functions and dialog boxes
Operation menu: functions and dialog boxes
The Operation menu allows you to control the operating mode, the recording functionality, and how the ST90 system transmits audio pulses ("ping") into the water.
Tx Power function
Use Tx Power to increase or decrease the output power. The output power is selected from predefined steps.

About this manual
The purpose of this publication is to provide the descriptions, procedures and detailed parameter explanations required to allow for safe and efficient use of the ST90 system. The publication also provides you with a thorough understanding of the parameters and adjustments provided by the ST90 system.
Simrad ST90
Operating procedures
Maintenance procedures
User interface
Menu system
Functions and dialog boxes
- Main menu: functions and dialog boxes
  The Main menu is located at the top of the menu structure. It offers the most common functions for efficient use of the ST90 system. Unless you hide the entire menu system, the Main menu is visible at all times, even if you close the secondary menus.
- Operation menu: functions and dialog boxes
  The Operation menu allows you to control the operating mode, the recording functionality, and how the ST90 system transmits audio pulses ("ping") into the water.
  - Operation function
    The Operation function controls the operating mode of the ST90 system. You can set it to Normal, Replay or Inactive.
  - Transmission Mode function
    Transmission Mode lets you to control how often the ST90 system shall transmit acoustic energy (ping) into the water. For normal use, choose Maximum. If you choose Maximum, the ST90 system will transmit (ping) continuously and as often as possible. This gives you the maximum refresh rate.
  - Tx Power function
    Use Tx Power to increase or decrease the output power. The output power is selected from predefined steps.
  - Record RAW function
    Record RAW allows you to record the unprocessed echo data received by the transducer. You can save the data to the hard disk, or onto an external storage device. The data files can be played back on the ST90 system. You can keep the recorded files for future reference, training purposes and calibration.
  - Record Processed function
    The Record Processed function allows you to record the processed echo data received by the transducer. Which processing to apply is controlled by the settings on the Processed Data to File page. Processed Data to File is located in the Output dialog box.
  - Output dialog box
    A key function of the ST90 system is its ability to export data. The purpose of the Output dialog box is to collect all functionality related to data output in one easily accessible location. The pages in the Output dialog box are described in a separate structure.
  - Audio function
    Select Audio to turn the audio output on or off.
- Display menu: functions and dialog boxes
  The Display menu provides basic functions related to the screen behaviour and presentation of the echo data. Use the Display menu to control the visual aspects of the system, and to show or hide various elements in the presentation.
- Setup menu: functions and dialog boxes
  The Setup menu provides basic functions related to the installation parameters and the communication with peripheral systems.
- Active menu: functions and dialog boxes
  The Active menu offers parameters related to current views and data presentations provided by the ST90 system.
- Secondary functions and dialog boxes
- Pages in the Output dialog box
  A key function of the ST90 system is its ability to export data. The purpose of the Output dialog box is to collect all functionality related to data output in one easily accessible location.
- Pages in the Display Options dialog box
  The Display Options dialog box is used to specify basic settings for the sonar presentation.
- Pages in the Environment dialog box
  Environmental parameters such as salinity, sound speed and water temperature all play an important part to present accurate echo data. Use the Environment parameters to define these values. Depending on the current sea and weather conditions, you may need to change these values frequently.
- Pages in the Diagnostics dialog box
  The ST90 system is a computerized sonar. There are hardly any analogue circuitry, and the possibility of traditional troubleshooting is limited. In order to rectify this, a built-in software application is available to offer test and maintenance functionality. The Diagnostics dialog box controls the test and diagnose application that checks the performance of the ST90 system.
- Pages in the Installation dialog box
  Before you use the ST90 system you must set it up to communicate with the relevant peripherals. Use the Installation dialog box to set up all interfaces with external devices, and to set up basic parameters related to installation and operation. In most cases, you only need to do this once.
- Pages in the Echogram dialog box
  The Echogram dialog box allows you to control the echogram presentation in the Inspection views. Two pages control the horizontal lines and the echogram type with applied TVG (time variable gain). One page controls how fast the echogram travels horizontally across the presentation.
- Pages in the Information Pane Options dialog box
  The ST90 system offers several information panes to provide additional and detailed data from the presentations. The information panes are opened and closed from the top bar. Several of the information panes are fitted with a Setup button. Select Setup to open the Information Pane Options dialog box. Use the Information Pane Options dialog box to change the operating parameters for the data provided in the information panes.
Concept descriptions
Technical specifications
The technical specifications summarize the main functional and operational characteristics of the ST90 system. They also provide information related to power requirements, physical properties and environmental conditions.
Datagram formats
The ST90 system can send and receive information to and from several different peripherals. All transmissions take place as datagrams with data sentences. Each datagram has a defined format and length.
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Tx Power function

Use Tx Power to increase or decrease the output power. The output power is selected from predefined steps.

How to open

This function is opened from the Operation menu.

Description

Tx Power is used to control the output power in the acoustic transmissions (pings). When the output power is reduced, the value of the attenuation is compared to the maximum output level (0 dB).

Off: No transmissions take place. The ST90 system does not ping. The ST90 is in Passive mode.
–[xx] dB: The source level of the acoustic transmission is reduced with [xx] dB related to the maximum output power.
Maximum: Select this option to enable maximum power level on all transmissions (pings).

Note:

Immediately after you have turned on the ST90 system, the Operation icon is flashing. The icon is flashing to indicate that even if the ST90 system is turned on, "pinging" is disabled. When the ST90 system is turned on, Tx Power is by default set to Off. This is a safety precaution to prevent inadvertent transmissions when the vessel is in dry dock.

Most users operate the ST90 system with Tx Power set to Maximum. This allows for maximum range, and works well in open waters with sufficient depth. Certain operating conditions may make it appropriate to adjust the output power.

Tip:

If you work in shallow and/or confined waters you may find it useful to reduce the output power to avoid reverberation.

Some of our users claim that reducing the output may be useful if you are looking for scattered fish.

If you work in vicinity of other vessels using hydroacoustic systems in the same frequency range as your ST90 system, interference may cause problems. Reducing the output power is not a practical way to deal with interference. It is more efficient to change the operating frequency.

To investigate unknown and/or unfamiliar targets, some user prefer to "reset" the ST90 system by turning off all the receiver filters and adjust the output power.

Move the cursor to either side of the button to change the setting. Select the left side of the button to decrease the value. Select the right side of the button to increase the value. You can also select the middle of the button to open a small menu with available options.