Guralp Systems Limited
MAN-MIN-0001 - Güralp Minimus - Technical Manual


1. Preliminary Notes 2. System Overview 3. System description 4. Getting started 5. Advanced system configuration 6. GüVü app 7. Advanced troubleshooting 8. Appendix 1 – Instrument/channel names 9. Appendix 2 – Minimus network ports 10. Appendix 3 – Connector pin-outs 11. Appendix 4 – Güralp Discovery installation 12. Revision History

Section Index: 5.1. System status 5.2. Station meta-data 5.3. I.P. address options 5.4. GDI auto-connection 5.5. Power monitoring 5.6. Data storage 5.7. Data transmission 5.8. Timing 5.9. Deploy mode: Full power-save 5.10. Configuration and control of connected digital instruments 5.11. Configuration and control of connected analogue instruments 5.12. Settingasensor orientation 5.13. Earthquake Early Warning 5.14. Using a registry 5.15. Updating Minimus firmware 5.16. Import / Export an existing configuration 5.17. Control Centre

Chapter 5. Advanced system configuration

Advanced system configuration control and configuration tools are available by selecting an instrument in Discovery, right-clicking its entry and selecting “View Web Page”. Alternatively, the web interface can be viewed by navigating to the LAN address of the instrument from any common web-browser.

5.1 System status

The “Status” tab of the web browser interface provides state-of-health information about the Minimus and connected instruments. These parameters are described as follows:

5.2 Station meta-data

Discovery provides a number of flexible station meta-data inputs. These are accessible from the “Setup” tab of the instrument’s web page.

Label” is used in Discovery only and appears in the list of instruments in the main window. The Label can also be edited by right-clicking on the instrument in the main window of Discovery and selecting “Edit Label”.

Station Name, Network Code and “Site Name are all standard meta-data header values used by the miniSEED file format, which will be included in locally-stored miniSEED files (see section 5.6).

5.3 I.P. address options

By default, the Minimus uses DHCP (Dynamic Host Configuration Protocol) to acquire its network configuration but static addressing can be used if required.

To configure static addressing, visit the “Network” tab of the instrument’s Web page and, under “DHCP”, change the mode from “DHCP” to “Static On” in the drop-down menu.

In this mode, it is possible to specify the I.P. address, the NetMask and the address of the Gateway (default router), as shown:

Before any changes made here will take effect, the Minimus must be re-booted. To do this, click the button on the “Data Record” tab

Network settings are also available in Discovery by right-clicking on the Minimus and selecting “Edit Network Address”.

5.4 GDI auto-connection

A Minimus normally acts as a server, where a client initiates a connection in order to pull data from it. This is the mechanism used when the GDI viewer in Discovery is launched.

The "GDI auto-connection" feature enables the Minimus to establish outgoing network connections in order to push data to one or more remote clients, such as Platinum systems or an Earthworm system running the gdi2ew plug-in.

To configure an auto-connection, type either the I.P. address or the host-name of the target client, a colon (':') and the port number (e.g. or, in any of the connection fields in the “Network” tab of the web page.

When auto-connection from a Minimus to a host is configured, the Minimus will attempt to open a connection to the host. If it fails, it will re-try every 60 seconds. A suitably configured host will accept the connection and the Minimus will then negotiate a link and start streaming data.

If the connection drops, the Minimus will attempt to reconnect every 60 seconds.

Note: The default port number for a gdi-link receiver is 1566. Push servers will normally connect to this port. The default port number for a gdi-link transmitter is 1565. Receivers wishing to pull data will normally connect to this port. See Chapter 9 for a list of the network ports used by the Minimus.

5.5 Power monitoring

The “Power” tab of the Minimus’s web page provides information about the supply voltage, as measured by the Minimus. The Minimus can be powered using either the power input connector (see section 10.2) or via the Ethernet connection (see section 10.1) using Power-over-Ethernet (PoE). The voltage measured at the PoE input is also displayed here.

5.6 Data storage

MicroSD cards need to be specifically formatted to operate with the Minimus. Cards supplied with Radian systems will have the correcting formatting applied in the factory, prior to shipping.

Data are stored on the microSD cards in the commonly-used MiniSEED format, in which each channel during a period of recording is saved as a single file. Instrument and station meta-data (e.g. instrument responses, coordinates, compression type etc.) are stored in the Dataless-SEED format.

Monitoring and configuration of data storage can be found in the “Data Record” tab of instrument web page. This page is organised into three main panels: microSD status, card formatting controls and channel recording configuration.

Note: When changing a setting in the Minimus web page, ensure that you wait for a few seconds before changing another setting. This allows time for the previous change to take effect.

The main panel of the "Data Record" tab in the web interface is shown here:

5.6.1 Recording status

The MicroSD card and data recording status can be monitored in the upper-most panel of the “Data Record” tab.

The left-hand column provides details of the external (primary, removable) microSD card and the right-hand column shows the status of the internal (backup) card.

microSD card and file storage status panel

Sections of this panel indicate the status of the following:

Note: After re-inserting an external microSD card, reload the Data Record page so that the card/recording status information can be updated with the new values.

5.6.2 MicroSD card re-formatting

The card re-formatting process fills the card with files containing zeroes and with place-holder names. When data are written, these files are renamed and then over-written with data.

There are two methods for card reformatting: “Quick format” and “Full format”. The quick format mode should be used for pre-deployment tests (e.g. stomp/huddle tests) to ensure that the instruments are operating properly. This mode simply marks existing files as empty without deleting their contents. Full formatting should be used prior to a long-term deployment to ensure that headers are included and files are fully clean before writing.

Note: A series of tests separated only by quick formats can leave some files with residual data in them. This is not normally a problem because a deployment will typically create data-sets longer than any test, over-writing any data remaining from the tests. Quick format

Ensure that the external microSD card is correctly inserted. Click the button: a dialogue box will appear to confirm the formatting operation – click the “OK” button to continue. The instrument web page will refresh and return to the “Status” tab. The reformatting operation is now complete. Full format

Ensure the external microSD card is correctly inserted. Click the button and a dialogue box will appear to confirm the formatting operation – click the “OK” button to continue. The process takes several hours: check the status indicators on the “Data Record” tab by refreshing the page: once the card status returns to "USABLE", the format is complete.

5.6.3 Channel recording set-up

In the “Output Rate SPS” column, drop-down boxes are available for each channel to either prevent the channel from recording (by selecting the “Disabled” option) or to select a sample rate. (You can stop all channels from recording by clicking the button).

After changing any sample rates, the Minimus will need to be restarted before the changes come into effect; this can be done by clicking the button.

A minimal web page is displayed during the reboot and the LEDs will flash the starting-up sequence (see section 3.1.1). Once the Minimus has successfully restarted, the full web browser display/controls will be available again.

5.6.4 Viewing recorded data

The “Storage” tab of the web browser interface displays the miniSEED files stored on the microSD card:

If the web page is accessed from a web browser, clicking on the file from the list automatically starts a download using your browser's standard mechanism:

Where the web page is launched from Discovery, it is necessary to copy the URL for the file (by right-clicking on it and selecting "Copy URL") and then pasting it into a web browser.

The microSD cards are formatted with empty files which are filled with data as they become available. The file-names are also changed when the files are written to. Until they are written to, they are marked as “hidden” files, so that it is easier to see how many files contain data when looking at the contents of the card.

Note: When viewing files in Windows Explorer, Güralp highly recommends that Hidden files are not shown. In Windows 10, this can be done by clearing the “Hidden items” check-box within the ribbon of Windows Explorer.

To view files saved on the external microSD card, insert the card into a microSD card reader (external or in-built) on your PC/laptop. Within a few seconds, the card should appear as a removable disk/drive.

The root directory of the disk contains five items:

The typical contents of the all_miniSEED_files_are_in_here directory looks like this:

The file-name consists of four components:

5.7 Data transmission

The monitoring and configuration of transmitted data is handled using the “Data Flow” tab of the instrument’s web page.

In the “Output Rate SPS” column, drop-down boxes are available for each channel to either select a sample rate or to exclude the channel from streaming (by selecting the “Disabled” option). All streaming can be stopped by clicking the button.

Upon changing the sample rate, the Minimus will need to be restarted for the changes to come into effect; this can be done by pressing the button.

During the reboot, the LEDs will flash, displaying the starting-up sequence (see section 3.1.1) and the Instrument Web Page will display the following screen.

Once the Minimus has successfully restarted, the full web browser display and controls will be available for use again.

5.7.1 Scream! (GCF format + Scream protocol)

The Minimus can act as a Scream! Server and streams data by sending GCF (Güralp Compressed Format) packets over a network connection using the scream data transmission protocol.

This is primarily intended to support Güralp’s Scream! Software (see section 4.3.2) or any software that can communicate using the Scream! Protocol, including SeisComP3.

These include:

Data can also be received by software that can communicate using the Scream! Protocol, including SeisComp3 and Earthworm.

Note: Güralp devices running the Platinum software can receive GCF data over the scream protocol, but the GDI-link protocol is strongly recommended for use in these cases.

5.7.2 GDI-link protocol

The Minimus can also transmit data using the GDI-link protocol. GDI-link can currently be used with:

GDI-link provides a highly efficient, low latency method of exchanging data via TCP between seismic stations and data centres. The protocol allows state-of-health information to be attached to samples during transmission. A receiver can accept data from multiple transmitters, and a single transmitter can send data to multiple receivers, allowing maximum flexibility for configuring seismic networks. GDI-link streams data sample-by-sample (instead of assembling them into packets) to minimise transmission latency.

A significant advantage of GDI-link is that it has the ability to stream data pre-converted into real physical units instead of just as raw digitiser counts.

For more information on GDI-link, please refer to Güralp manual SWA‑RFC‑GDIL.

5.7.3 SEEDlink protocol

The Minimus can act as a SEEDlink server to send miniSEED data packets over a network connection.

The SEEDlink server is enabled by default. It is possible to disable or re-enable. The server has a configurable back-fill buffer.

a debug mode produces additional messages in the seedlink.log that can be useful for debugging purposes.

Note: The Minimus SEEDlink back-fill implementation is packet-based.

In the “Network” tab of the Minimus' web-page, select the desired SEEDlink mode. The “Disabled” option turns off the SEEDlink server. Otherwise, "debug" mode is available with backfill buffer sizes of 256 KiB, 1 MiB, 32 MiB or 68 MiB (304 MiB is listed but not implemented) and normal mode ("Enabled") is available with backfill buffer sizes of 1 MiB, 32 MiB or 68 MiB.

Note: As a general guide, we find that 68 MiB is normally sufficient to store around one day of triaxial, 100 sps data.

To test the SEEDlink server, Güralp recommends using the slinktool software for Linux, which is distributed by IRIS. For more information and to download a copy, see

To show a list of available miniSEED streams, issue the command:

slinktool -Q IP-Address

Which produces output like the following:

DG TEST  00 CHZ D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  01 HHZ D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  00 CHN D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  01 HHN D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  00 CHE D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  01 HHE D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  00 MHZ D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  00 MHN D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

DG TEST  00 MHE D 2016-09-13 10:42:18  -  2016-09-13 10:46:56

To print miniSEED data records of a single channel, you will need the following command:

slinktool -p -S DG_TEST:00HNZ.D IP-Address

Which produces the following output:

DG_TEST_00_HNZ, 412 samples, 100 Hz, 2016,257,10:43:42.000000 (latency ~2.9 sec)

DG_TEST_00_HNZ, 415 samples, 100 Hz, 2016,257,10:43:46.120000 (latency ~2.6 sec)

DG_TEST_00_HNZ, 416 samples, 100 Hz, 2016,257,10:43:50.270000 (latency ~3.0 sec)

DG_TEST_00_HNZ, 413 samples, 100 Hz, 2016,257,10:43:54.430000 (latency ~2.6 sec)

DG_TEST_00_HNZ, 419 samples, 100 Hz, 2016,257,10:43:58.560000 (latency ~3.0 sec)

DG_TEST_00_HNZ, 418 samples, 100 Hz, 2016,257,10:44:02.750000 (latency ~2.6 sec)

DG_TEST_00_HNZ, 415 samples, 100 Hz, 2016,257,10:44:06.930000 (latency ~3.0 sec)

The SEEDlink server on the Minimus also supports the use of the “?” character as a wild-card within network, station and channel codes. This allows you to request multiple streams using a single command.

Note: Because the ? character has special meaning to the shell, it is safest to quote this character with a preceding backslash ('\') when used in command arguments.

5.8 Timing

The Minimus system supports timing provided through an attached GNSS receiver or, if that is not available, using Network Timing Protocol (NTP) or Precision Time Protocol (PTP). The currently supported GNSS systems are Navstar (GPS), GLONASS and BeiDou.

5.8.1 GNSS lock status

This is available in the “Status” tab of the instrument’s Web page.

A number of GNSS reporting parameters are given, including:

5.8.2 Precision Time Protocol (PTP)

The Minimus system supports timing provided through PTP. The IEEE 1588 Precision Time Protocol is used to synchronise clocks across a computer network. It is significantly more accurate than NTP but generally requires specialised hardware support. PTP can be configured for multicast or unicast mode. In unicast mode, the server IP address must be specified.

This is available in the “Status” tab of the digitisers Web page. A number of reporting parameters are given, including: Special notes for PTP with Maris ocean-bottom systems.

PTP is the only source of timing available for a deployed Maris digitiser. To configure, visit the “Network” tab of the digitiser web page. Under the heading “Network config” are four options:

Select the option “Run always – Override GPS” before the deployment of the Maris cabled system. PTP offset corrections

If your PTP infrastructure produces a fixed offset (when compared with GNSS), a manual correction can be applied to compensate for this.

The required correction value can be extracted from the internal clock from GNSS stream of the Minimus. In the Live View enable the 0CGPSO channel and select at least 20 minutes of data. Right-click on the selection and click on Show Samples:

0CGPSO channel is Discovery live view

At the top of the resulting window, the maximum (max), average (avg) and minimum (min) values are displayed:

Note the value of the average, multiply by -1 and enter the resulting value in the PTP Offset Correction box in the Network Timing section of the Network web page.

5.8.3 Network Timing Protocol (NTP)

By default, the NTP server option under the “Setup” tab of the instrument’s web page is set to “Pool” which uses the virtual server pool

Alternatively, it is possible to set the I.P. of your preferred NTP server. To do this, select the “Static” option from the “NTP server” drop-down menu, which activates the “NTP IP Addr” setting; add your NTP server’s I.P. address here.

5.9 Deploy mode: Full power-save

The Minimus digitiser offers two deployment modes: "Normal" and "Full power-save". "Full power-save" mode makes a number of configuration changes in order to reduce the unit's power consumption. This mode is particularly useful when using Maris digital ocean-bottom sensors.

The desired mode can be specified using the “Deploy mode” drop-down menu in the “Setup” tab of Minimus web page. Changes are not applied immediately.

"Full power-save" mode temporarily disables auto-centring of a connected the Maris digital sensor, so that it is not continually re-centring while being lowered to the sea floor. When this mode is selected, the “Auto Centre Disable (hr)” input field appears: use this to specify the length of time before auto-centring is re-enabled.

Note: Güralp recommend a value of 10 to 12 hours to fully cover the entire deployment procedure.

The final step is to click on the button and confirm or cancel the operation from the pop-up window that appears.

A 30 seconds count-down will start before entering the system in power-save mode. The screen changes and a new button is added:

You can cancel the operation before the countdown is complete by clicking the button.

Caution: The power-save mode will disable the Ethernet and GNSS modules. You will not be able to continue to use the web interface.

Once in deploy mode, the only way to re-enable the Ethernet module is to connect to the Minimus via a serial connection (see section 7) or to use the GüVü Bluetooth app (see section 6.4).

When a serial or Bluetooth connection is established, type the command powersave off in the console to disable the "Full power-save" mode and re-enable Ethernet communication.

5.10 Configuration and control of connected digital instruments

Please refer to Section 7 of MAN-RAD-0001 for full details on configuring and controlling digital instruments (e.g. a Güralp Radian) connected to the Minimus.

5.11 Configuration and control of connected analogue instruments

5.11.1 Setting instrument (sensor) gain for Güralp Fortis

The Güralp Fortis strong-motion accelerometer features a remotely-switchable gain option that can be controlled from inside Discovery. First, ensure that physical gain switch on the underside of the Fortis is set to position “3” (as indicated by the engraving). See MAN‑FOR‑0001 for more details.

To change the gain electronically, first, set the “Instrument Type” to “Fortis”. Setting this option will then enable the “Instrument Gain” control. Under the “Instrument Gain”, select a gain setting (options: 0.5g; 1g; 2g; 4g).

Setting the instrument type to “Fortis” will also change the miniSEED channel names to indicate that data are recorded from an accelerometer, e.g. “HNZ”.

5.11.2 Setting digitiser gain

The input gain can be controlled from the "Setup" tab of the web page using the “Input Gain” drop-down box. Digitiser gain options available are: Unity, ×2, ×4, ×8 and ×12.

5.11.3 Mass control

The Minimus allows control of mass centring and locking for connected instruments. Mass centring

Many broadband seismometers (e.g. Güralp 3T and 3ESPC) support remote/electronic mass centring. Mass centring can be controlled from the "Setup" tab of the web page using the “Recentre” button.

Note: “Instrument Type” must be set to “Generic” for the mass lock control buttons to be visible.

The "Busy line status" will be shown in red for the duration of the operation.

Mass centring status and control can also be found in the Centring tab of the instrument Control Centre window. Mass locking

Some seismometers require their masses to be locked for transportation. Mass locking can be controlled from the "Setup" tab of the web page using the “Lock” and “Unlock” buttons.

Note: The mass lock control buttons are not displayed unless the “Sensor Type” is set to “Generic”.

5.11.4 Instrument response parameters

Calibration is a procedure used to verify or measure the frequency response and sensitivity of a sensor. It establishes the relationship between actual ground motion and the corresponding output voltage. Calibration values, or response parameters, are the results of such procedures.

Response parameters typically consist of a sensitivity or "gain", measured at some specified frequency, and a set of poles and zeroes for the transfer function that expresses the frequency response of the sensor. A full discussion of poles and zeroes is beyond the scope of this manual.

The gain for a seismometer is traditionally expressed in volts per ms-1 and, for an accelerometer, in volts per ms-2. Other instruments may use different units: an electronic thermometer might characterise its output in mV per °C.

A calibration procedure is also used to establish the relationship between the input voltage that a digitiser sees and the output, in counts, that it produces. The results are traditionally expressed in volts per count. Each Minimus is programmed at the factory so that it knows its own calibration values.

Although the Minimus automatically receives calibration parameters from connected digital instruments (e.g. Güralp Radian), calibration values need to be entered manually for connected analogue sensors (e.g. Güralp Fortis).

To enter the calibration values for your analogue instruments, right-click the Minimus in Discovery’s main window and select “Calibration” → “Calibration Page Editor”.

This form has one tab for each component. The instrument's response values should be entered here. These are:

The calibration parameters for one component can be copied to other components of the same instrument, or other instruments. This is especially useful for poles and zeros, because they are typically identical for all three components of all instruments in a class. The drop-down menu at the left of the button allows selection of what to copy: poles and zeros, gains or everything. The destination sensor and component(s) can be selected in the subsequent drop-down menus.

The overall system calibration parameters can be exported and saved in a file for future use by clicking on the button. The resulting file-name will have the extension .conf. Values from an existing calibration file can be imported using the button. The associated drop-down menu allows specification of what to import: poles and zeros, gains or everything.

When transmitting MiniSEED data, the responses of the instruments and digitisers are encoded in a message called a “data-less SEED” volume. The contents of these volumes can be displayed in human-readable form, known as RESP, by clicking on the “RESP file” link of each channel in the “Data flow” and “Data record” tab of the Minimus web page.

Clicking on a RESP file link produces a page like this:

Right-click anywhere and select “Back” to return to the Minimus web-page.

To save a RESP file, right click on it in the main list and select "Save Link":

5.12 Setting a sensor orientation

A Matlab extension for Scream! allows easy determination of the exact orientation of a sensor relative to a surface reference sensor (which can be installed accurately aligned with the Earth’s magnetic field North).

The complete description of the procedure is explained in the following page

The Relative Orientation extension of Scream! provides a correction angle that can be entered into the Sensor Orientation section of the Minimus web page.

This feature can be applied to analogue seismometers and accelerometers and also when either Borehole or Post-hole Radian are installed in a vertical orientation.

5.13 Earthquake Early Warning

The “Trigger” tab is dedicated to Earthquake Early Warning settings. These are disabled by default because of the amount of processing resource - and hence, power - consumed by triggering calculations.

The Earthquake Early Warning subsystem can be enabled using the drop-down menu at the top of the "Trigger" page of the web interface.

The heart of the Earthquake Early Warning subsystem is an STA/LTA (Short-Time-Average divided by Long-Time-Average) triggering algorithm. The algorithm continuously calculates the average values of the absolute amplitude of a seismic signal in two simultaneous moving-time windows. The short time average (STA) is sensitive to seismic events while the long time average (LTA) provides information about the current amplitude of seismic background noise at the site. When the ratio of STA to LTA exceeds a pre-set value (the parameters can be set, as seen in the picture below), an event is “declared”.

The following parameters can be configured:

When a trigger is declared, the system will issue messages using the Common Alerting Protocol. For the full specification of this protocol, please refer to

Various parameters control how the CAP message is created.

These are:

The Triggers section of the web page enables the user to configure the triggering system. The trigger source should be configured first because different configuration options are displayed for different source types. Once the source-specific settings are configured, the destination should be specified. Destinations can be shared between sources, allowing the creation of networks (directed graphs) of systems for distributed event detection.

5.13.1 Trigger sources

The available sources are listed below, along with the configurable fields available in each case.

5.13.2 Trigger destinations

The options available form the various Destination fields are:

5.13.3 Derived Streams

The various calculated averages used in the triggering algorithm can be displayed as streams in Discovery’s live streaming window. This can be used to help decide appropriate triggering parameters. The available streams are:

Note: Each time an event is detected and the trigger is enabled, the LED on the top of the Minimus will flash blue once.

5.13.4 CAP receiver

Güralp Discovery includes a CAP (Common Alerting Protocol) receiver. It listens on a specified UDP port for incoming CAP messages. When one arrives, it is displayed and plotted on a map. In addition, the receiver can open a TCP connection to the cloud-based registry server and display CAP messages that have been sent to the registry server. See section 5.14 for information about configuring a registry server.

All CAP messages are stored in a log-file. The full message is recorded so that it can be re-loaded later, if required.

The CAP receiver functionality is accessed using the context (right-click) menu in Discovery or clicking on “Edit” in the menu bar:

The CAP receiver window allows specification of the listening port. Each Minimus from which messages should be received must have this value specified as the “CAP Port” in its triggering settings (see section 5.13.2 on page 58). The value should be between 1025 and 65535. You should avoid numbers in the list at

The reception of CAP messages can be enabled or disabled clicking on the button at the top, right-hand side of the window.

If you wish to forward the CAP messages to a server, type its IP address into the field and tick the check-box named “Use forwarding server”. An error message is displayed if the entered IP address is not valid.

To log CAP messages to a file, tick the “Log events” check-box and use the button to select an appropriate location for the database file.

To import an existing database of events, first enable logging, then browse to the file using the button and, finally, click the button to load the file. If no file is specified, the logging is automatically switched off and a pop-up message is displayed.

When an event is detected and a CAP message is received, the location of the Minimus that generated the trigger is identified by a pointer displayed on the map. The events and the information contained in the CAP message are displayed at the right-hand side of the window. This includes the SEED identifiers, network, station, channel and location, along with the time, the recipients and the threshold value which was exceeded.

Click on the button to clear markers from the map and descriptions from the right-hand-side list. This action does not affect the contents of the log-file.

5.14 Using a registry

Discovery can maintain a list of Minimus digitisers in a local or cloud-based registry, simplifying management of medium to large networks and removing the need for static IP addresses at telemetered stations. Registered digitisers appear in the selection list in the main screen, regardless of whether they are on the local network or not.

Administrators can create their own registry servers by installing a simple program on a server. The server itself must have a static IP address and be accessible to all connected Minimus units, as well as the PCs running discovery. Registry servers programs are currently available for Linux and Windows. Please contact Güralp technical support for details.

For administrators not wishing to install their own registry, Güralp provide a shared registry server in the cloud at which customers are welcome to use.

Registered digitisers must be assigned to groups, each of which has a Group Identifier. Instances of Discovery must also be configured with a Group ID and can only display registered digitisers from the matching group. This allows partitioning of large networks into smaller administrative domains. It also makes possible the simultaneous use of the Güralp shared registry server by multiple organisations.

To use a registry:

5.14.1 Configuring a Minimus for use with a registry

The address of the registry server and the chosen Group ID must be set individually for each participating Minimus digitiser.

To do this, first connect the Minimus to the same network as a PC running Discovery and click the button, so that the Minimus appears in the main Discovery list. Right-click () on the digitiser’s entry and select “View Web Page” from the context menu:

In the resulting web page, select the “Network” tab. The Registry parameters can be found near the bottom of the resulting screen:

These are:

Once you have set the correct values, the digitiser must be rebooted before they will take effect. To do this, click the button.

5.14.2 Configuring Discovery for use with a registry

To specify a registry server for an instance of discovery, type its address into the field at the bottom left of the main screen:

To set the Group ID in Discovery:

Return to the main windows and test the configuration by clicking the button. All Minimus digitisers using the same Registry server and Group ID should appear in the main list.

5.15 Updating Minimus firmware

The firmware of the Minimus is upgradeable. New releases appear regularly – mostly to add new features but, occasionally, to fix problems. Güralp recommends that the Minimus is regularly checked for availability of firmware updates and, when convenient, these updates should be installed.

The procedure below guarantees a straightforward upgrade and prevents any data loss or misconfiguration.

5.15.1 FPGA Firmware update

The Minimus uses a field-programmable gate array (FPGA) to implement some of its functionality. This has its own firmware, separate from the main firmware.

An image of the FPGA firmware is included in the Minimus firmware, allowing the FPGA to be updated to the version included in the loaded Minimus firmware. To upgrade it to the latest version, first upgrade the Minimus’ main firmware and then follow the instructions below.

Caution: Any interruption during the update can cause a serious malfunction of the Minimus, requiring it to be returned to the factory for reprogramming. We recommend that updates are only performed when requested by Güralp’s support staff.

In Minimus web page, select the “Setup” tab. Ensure that the “FPGA update sensor” drop-down menu at the bottom of the page is set to “Digitiser”. Click on the button to start the updating process.

The first phase is called “Parking”, during which the firmware is written to the module from the most recent version available. A percentage value in brackets shows the status of the process. It takes around 15 minutes to reach the 100%.

The second phase is called “Programming”, it lasts only a few minutes and at this stage the FPGA is actually programmed with the new firmware.

When the procedure is completed the status is marked as “Programming finished”. At this point the Minimus must be manually power-cycled by removing and then, after a minute, reconnecting the power.

Normally the status is “Idle” but, when the Minimus is turned on, it checks if the upgrade went well and if the FPGA is responding to commands. During this operation the status appears as “Busy”.

5.16 Import / Export an existing configuration

Updating the Minimus’ firmware can, occasionally, cause loss of configuration. We recommend that you export and save the current configuration before proceeding with an upgrade. This operation can be done through Discovery by right-clicking on the digitiser in the list and selecting “System Configuration” from the context menu:

Select "Use configuration from one of the devices". If more than one device is available, select the one from which the configuration should be downloaded. Click the button and browse to a suitable location (on your PC) into which to save the configuration file.

After the firmware update is successfully completed, the previous configuration can be imported, if required, by following the instructions below.

Right-click on the digitiser’s entry in the Discovery list and select "System Configuration" from the context menu. Select the "Use configuration from file" option.

Select the configuration file from where it was saved in the File Explorer and confirm. Use the check-boxes to select the devices to which the configuration should be uploaded and click on the button.

Wait until the process finishes. To apply the new configuration, the unit has to be rebooted: the button can be used to perform the required system restarts.

5.17 Control Centre

Several actions can be taken from within Discovery to control any of the instruments connected to the Minimus as well as the digitiser itself.

This operation can be done by right-clicking on the digitiser’s entry in the list and select “Control Centre” from the context menu.

The “Status of health” tab provide information about the general state of the digitiser, its serial number and IP address, its up-time (time since last boot) and GNSS status.

The “Terminal” button launches a console that allows interactions with the command line of the Minimus. The list of available commands and their respective descriptions can be displayed entering the command “help”. This should generally only be done on the advice of the Güralp technical support team.

The “Webpage”, “Map” and “Live data view” have equivalent functions to the “View Web Page”, “Show on Map” and “Live View” entries in the context (right-click) menu of the Minimus in the Discovery main window.

Please refer to Section 5.5 of MAN‑RAD‑0001 for full details on the Radian hole-lock control.

The “Centring” tab allows manual centring of the analogue and digital instruments (e.g. Radian) connected to the Minimus. In the case of the Radian, when the command is issued, the three sensors start centring, one at a time. Firstly, the rough mechanical centring takes place. It is then followed by a fine electronic centring sequence. Refer to Section 7.25 of MAN‑RAD‑0001 for full details.


1. Preliminary Notes 2. System Overview 3. System description 4. Getting started 5. Advanced system configuration 6. GüVü app 7. Advanced troubleshooting 8. Appendix 1 – Instrument/channel names 9. Appendix 2 – Minimus network ports 10. Appendix 3 – Connector pin-outs 11. Appendix 4 – Güralp Discovery installation 12. Revision History