Purpose
Document information
About this manual
The purpose of this publication is to provide the descriptions and procedures required to allow for efficient use of the ST90 system. The manual does not contain detailed information about functions, dialog boxes and operating parameters.
Simrad ST90
Operating procedures
- Getting started
- Choosing operating mode and key transmit parameters
  - Selecting Normal mode to start pinging
    In order to transmit ("ping"), you must set the ST90 system to Normal operating mode. This is the default mode when the ST90 system is turned on.
  - Selecting Replay mode
    Replay mode allows you to play back previously recorded raw data. The ST90 system cannot operate normally while in Replay mode. Neither transmission nor reception takes place.
  - Selecting Inactive mode
    Inactive mode is provided to pause the operation temporarily. Neither transmission nor reception takes place. The current echoes are removed from the display presentation.
  - Setting up the ST90 system for maximum echo refresh rate
    You can set up the ST90 system to transmit (ping) as often as possible. This gives you the maximum refresh rate.
  - Transmitting single pings
    You can set up the ST90 system to transmit a single ping only when you want it.
  - Transmitting with fixed-time intervals
    You can set up the ST90 system to transmit pings with a fixed time interval.
  - Adjusting the output power to match varying conditions
    You are permitted to adjust the output power from the ST90 system. Tx Power is used to control the amount of power that is transmitted with each ping.
  - Selecting the best operating frequency
    The Frequency function is used to control the centre frequency of the acoustic transmissions (pings). You can select any operational frequency from 14 to 24 kHz. All types of noise matter when you wish to find the best operating frequency.
- Controlling the gain and range settings
- Using the markers and tracking features
- Improving the recognition of fish and schools using receiver filters
- Recording and replaying echo data
- Recording and exporting processed echo data
- Capturing the display presentation in image and video files
- Setting up presentation modes and views
- Defining the visual information in the sonar views
- Defining settings related to user preferences and individual customizing
- Saving, retrieving and maintaining user settings
- Defining the user-selected features on the Operating Panel
- Exporting sensor data, marker positions and technical information
User interface
Menu system
Functions and dialog boxes
The functions and dialog boxes provided in the ST90 user interface are not described in this publication.
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.
Copyright

Transmitting with fixed-time intervals

You can set up the ST90 system to transmit pings with a fixed time interval.

Use Transmission Mode to control how often the ST90 system shall transmit its energy into the water. For normal use, choose Maximum. If you choose Maximum, the ST90 system will transmit (ping) continuously and as often as possible.

If you choose Interval, you must define the time between each ping with the Ping Interval function. Ping Interval permits you to choose the time (in milliseconds) between each transmission (ping).

Procedure

Open the Operation menu.
Set Operation to Normal.
Set Transmission Mode to Interval.
Specify the interval between each ping.
1. Select either side of the button to choose a value.
2. Select the middle of the button to open it.
  If you have a keyboard connected to the ST90 system, type the requested value.
You can also change the value by selecting - and holding - the middle of the button, and move the cursor sideways. Drag the cursor sideways to increase or decrease the value. Release the mouse button when requested value is shown.