Alarms in Hydromagic

In Hydromagic, alarms can be configured to alert you or stop recording a raw data file, when specified conditions are not met. Alarms can be applied to GNSS accuracy, position, speed, navigation errors, echo sounder depth, USV operation, and boundary (geofencing).

We recommend using at least the alarm for GNSS accuracy, to avoid recording invalid data for hours. For instance, when the RTK fix has been lost, you want to know this immediately to avoid recording with invalid tide or elevation values.To set up alarms, first select the 'Preferences...' item from the "Options" menu to open the preferences dialog. In the preferences window, please select the "Alarms" tab to setup alarms:

In the preferences window, select the "Alarms" tab.

GNSS or RTK receiver alarms

To set up alarms on the GNSS/RTK equipment, click the 'Setup...' button in the "GNSS Alarm" section. To enable alarms for GNSS, check the "Enable alarm on invalid and inaccurate GNSS positions" option. You will now be able to configure other options:

GNSS alarms configuration

Minimum quality value

Use this option to make sure only positions are recorded when the GNSS is, for instance, in RTK Fixed or differential mode. Possible values include:

• No Fix;
• GNSS Fix;
• Differential Fix (WAAS, EGNOS or SBAS);
• RTK Float;
• RTK Fixed.

When using tide corrections using RTK, it is recommended to use this option with "RTK Fixed" selected, so you will be notified when RTK tides are disabled.

Minimum satellite count

This option can be used to use only position fixes with a minimum number of satellites in view to ensure accuracy. For a valid 2D fix, at least 3 satellites are required, for a 3D fix, you need at least 4 satellites. It is recommended to set this value to 6 or higher. For RTK at least 5 satellites are required.

Maximum HDOP value

Activates alarm when the HDOP (Horizontal Dilution of Precision) value exceeds a defined threshold. Recommended value is 2.0.

Maximum correction age

The correction age indicates the age of the correction data in seconds. When this value increases, it often means that the differential GNSS or RTK correction signal is temporarily lost. In most scenario's this value will not exceed the value of 5-6. It is recommended to set this value to 10.

Require beacon id

This option can be used when a DGNSS or RTK correction signal is used. When another beacon is received then the one that is expected, it may result in inaccurate positions, for instance when a reference station is at a to great distance. Set this value to the beacon ID displayed directly after a successful setup of your reference station. This option isn't generally used. If unsure how to use it, just enter zero for this value.

Maximum horizontal error

Monitor the calculated horizontal error as reported by your GNSS receiver. To use this feature, the "$GNGST" NMEA0183 sentence must be enabled, otherwise this value will be ignored, since the reported error will always be zero.

Maximum vertical error

Monitors the calculated vertical error as reported by your GNSS receiver. To use this feature, the "$GNGST" NMEA0183 sentence must be enabled, otherwise this value will be ignored, since the reported error will always be zero.

Display Text

This setting is optional and can be used to override the default alarm text (which is "ALARM"). You can enter, for instance: "GNSS INACCURACY" here so when an alarm sounds, you instantly know it must have something to do with your GNSS receiver.

Sounder alarms

To set up alarms on the echo sounder equipment, click the 'Setup...' button in the "Sounder Alarm" section. To enable alarms for sounders, check the "Enable alarm on invalid and out-of-range soundings" option. You will now be able to configure other options:

Echo sounder alarms configuration

Minimum depth

Sets the minimum depth that is expected to be returned from the echo sounder. This value is not corrected, but compared to the raw depth returned.

Maximum depth

Sets the maximum depth that is expected to be returned from the echo sounder. This value is not corrected, but compared to the raw depth returned.

Display Text

This setting is optional and can be used to override the default alarm text (which is "ALARM"). You can enter, for instance: "INVALID DEPTH VALUE" here so when an alarm sounds, you instantly know it must have something to do with your echo sounder readings.

Multiple transducer systems

When using a multi-transducer system, for instance, the Unabara Z-Sweep system as the source of the recorded depths, the 'Multiple Transducers..' button should be visible. When entering values in this dialog, the minimum and maximum value in the main "Sounder Alarms" dialog will be ignored. The per transducer range will become leading.Clicking this button allows you to configure minimum and maximum values for each of the up to eight transducers. This can be useful when transducers which are mounted under an angle are allowed to report a higher depth value (slant range in that case).

Multiple transducer ranges will override the main low and high depth alarm settings

Speed alarm

When performing a survey, it is important to limit the speed of your vessel. The maximum recommended speed is approx 3 miles or 5 kilometers per hour. Higher speeds can result in less accuracy of your measurements (because of timing(latency) issues). To set up an alarm on the speed of the vessel, click the 'Setup...' button in the 'Speed Alarm' section. To enable an alarm for speed, check the "Enable alarm on speed limit" option. You will now be able to configure other options:

Speed alarm configuration

Boundary alarm

To setup an alarm on a boundary, click the "Setup..." button in the "Boundary Alarm" section. To enable an alarm for a boundary, check the "Enable alarm on vessel position" option. You will now be able to configure other options:

Boundary alarm configuration

Selected boundary

The selected boundary is used to check the vessel position. When the vessel is outside of the selected boundary, the alarm will be triggered.

Display Text

This setting is optional and can be used to override the default alarm text (which is "ALARM"). You can enter, for instance: "VESSEL OUTSIDE BOUNDARY" here so when an alarm sounds, you instantly know you are leaving a predefined area.

Cross Track alarm

The cross-track error is the distance from a planned line. This is the same distance as displayed in the Helmsman Display (also known as LR Indicator). To set up an alarm on cross track errors, click the "Setup..." button in the "Cross Track Alarm" section. To enable an alarm for cross track errors, check the "Enable alarm on cross track error" option. You will now be able to configure other options:

Cross Track Error (XTE) alarm configuration

Maximum Distance

Enter the maximum distance from the planned line. When the vessel is more than this distance from the line, the alarm will be triggered.

Display Text

This setting is optional and can be used to override the default alarm text (which is "ALARM"). You can enter, for instance: "OFF COURSE" here so when an alarm sounds, you instantly know you are too far away from the selected planned line.

USV alarm

The USV alarm can be used to alert you when the batteries of your USV run out of energy. This option can only be used when an ArduPilot autopilot is used and connected using the "MAVLink communication plugin". To setup an alarm on battery condition errors, click the "Setup..." button in the "Drone / USV Alarm" section. To enable an alarm for problems with your USV's batteries, check the "Enable alarm on USV battery conditions" option. You will now be able to configure other options:

USV battery alarm configuration

Minimum battery voltage

Enter the minimum battery voltage (in Volts) for the onboard batteries. When the voltage drops below this threshold, the alarm will be triggered.

Maximum battery current

Enter the maximum battery current (in Amperes) for the onboard electronics (including motors). When the current exceeds this threshold, the alarm will be triggered.

Maximum system temperature

Enter the maximum allowed temperature for a system (USV, echo sounder, or computer board). Currently this is only supported on the CEE-USV via the CEESCOPE plugin. When the value is set to zero, no temperature check will be performed. The temperature units can be changed via the "Unit settings" tab.

Game controller or RC Transmitter

This new alarm, introduced in Hydromagic version 2024, warns you when your Xbox controller or RC Transmitter is out of range, or the battery voltage drops. To be able to control your USV, you have to resolve the issue. You can choose to pause the sounding until the USV can be controlled again. To use this feature, you must use the "Game Controller (Xbox) plugin". The voltage level is only reported when using the dedicated Xbox wireless dongle. It is not reported over Bluetooth connections.

Display Text

This setting is optional and can be used to override the default alarm text (which is "ALARM"). You can enter, for instance: "USV BATTERY" here so when an alarm sounds, you instantly know that there is a problem with the USV's batteries.

ACTION: Pause recording

When the 'Pause sounding recording' option is enabled, the recording of the current sounding is suspended when the alarm is activated. You must press the record button again to resume recording. This feature is available for all alarms discussed above.

ACTION: Sound alarm

When the 'Sound alarm' option is enabled, then a sound is played when the alarm is activated. In addition to the sound, a big red banner with the text 'ALARM' (or the user-defined text) is displayed in the map view. This feature is available for all alarms discussed above.

To make sure you will always see the visual alarm banner, make sure the screen doesn't go into sleep mode. You can change this behavior via the "System settings". In the system settings window, check both the "Disable Windows Screensaver activation" and "Disable Windows Powersaver activation" options. When exiting Hydromagic, the computer will continue using the system's power settings.

When an alarm triggers, either "ALARM" or the user defined text will be displayed.

You can reset the alarm by clicking the reset alarm button in the tool bar:

The reset alarm button will be enabled when the alarm is triggered.

NOTE: When using sound alarm(s), make sure your sound hardware is enabled and the volume is turned on.