Güralp Minimus2 User manual

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Güralp Minimus2
including Güralp Discovery software and the
GüVü app
Technical Manual
Document Number: MAN-MIN-0002
Issue A – Dec 2022

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Table of Contents
1Preliminary Notes 6
1.1 Proprietary Notice 6
1.2 Cautions and Notes 6
1.3 Manuals and Software 6
1.4 Conventions 6
2System Overview 7
2.1 Key features 7
2.2 Typical applications 7
3System description 8
3.1 Güralp Minimus2 digitiser 8
3.1.1 LED indicator 8
3.1.2 Bluetooth connectivity 8
3.1.3 Data storage 9
3.1.4 Web interface 10
3.2 Accessory package 11
3.2.1 Ethernet cable 11
3.2.2 Compact GNSS receiver and cable 11
3.2.3 Power cable 11
3.2.4 Diagnostic GNSS to Serial cable adapter 12
3.3 Güralp Discovery software 13
3.4 Güralp GüVü Android and iOS app 14
4Getting started 15
4.1 System set-up 15
4.2 Güralp Discovery software installation 15
4.3 Viewing waveforms and system state-of-health 17
4.3.1 Using Discovery’s “Live View” window 17
4.3.2 Using Scream! 20
5System configuration 22
5.1 Web Page login 22
5.2 System status 22
5.3 Data streams 23
5.4 Station meta-data 24
5.5 Network configuration 24
5.5.1 IP address and gateway 24
5.5.2 NTP (Network Timing Protocol) configuration 25

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5.6 GDI push (auto-connection) 25
5.7 Data storage 26
5.8 Storage 27
5.8.1 Recording status 27
5.8.2 MicroSD card data flushing and unmounting 29
5.8.3 Downloading recorded data 29
5.8.4 Downloading data for specific time-intervals 30
5.8.5 Bulk data extraction 30
5.8.6 The contents of the microSD card 31
5.8.7 Time based download via Network 33
5.8.8 Request data from microSD card via Network 33
5.9 Data transmission 33
5.9.1 Scream! (GCF format + Scream protocol) 34
5.9.2 GDI-link protocol 35
5.9.3 SeedLink Protocol 35
5.10 Synchronisation of the sample-clock 38
5.10.1 GNSS lock status 39
5.10.2 PTP (Precision Time Protocol) 39
5.11 Deploy mode: Full power-save 39
5.12 Configuration and control of connected analogue instruments 41
5.12.1 Setting instrument type 41
5.12.2 Setting instrument (sensor) gain for Güralp Fortis 41
5.12.3 Setting digitiser gain 41
5.12.4 Mass control 42
5.12.5 Instrument response parameters 42
5.13 Configuration and control of connected digital instruments 46
5.13.1 Inject a calibration signal 46
5.14 Earthquake Early Warning 47
5.14.1 Trigger Configuration 47
5.14.2 EEW Configuration 48
5.14.3 CAP receiver 48
5.14.4 Seismic Event Table 50
5.15 Using a Registry 51
5.15.1 Configuring a Minimus2 for use with a registry 51
5.15.2 Configuring Discovery for use with a registry 52
5.15.3 Registry mode: using WAN or LAN addresses 53
5.16 Updating Minimus2 firmware 54
5.17 Import / Export an existing configuration 54
5.18 Control Centre 55
6GüVü app 57
6.1 Getting started 57
6.2 Selecting data sources 57
6.3 View settings 58
6.4 Instrument control 58
6.4.1 Setting the PIN code 59
6.5 Emailing a deployment report 59

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7Advanced troubleshooting 60
7.1 Reset all settings during boot phase 61
8Appendix 1 – Instrument/channel names 62
9Appendix 2 - Digital interconnectivity and devices 63
10 Appendix 3 – network ports 64
11 Appendix 4 – Connector pin-outs 65
11.1 Ethernet 65
11.2 Power 65
11.3 GNSS/serial 67
11.4 Digital 67
11.5 Analogue 1 and Analogue 2 68
12 Appendix 5 – Dimensions and drawings 70
12.1 Minimus2Error! Bookmark not defined.
13 Appendix 6 – Güralp Discovery installation 71
13.1 Installation in Linux 71
13.2 Installation in Mac 72
13.3 Installation in Windows 73
13.4 Configuring Windows Firewall 75
13.5 Update 77
14 Appendix 6 – IP address configuration on PC or Laptop 80
14.1 On Linux 80
14.2 On macOS 80
14.3 On Windows 82

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15 EU Declaration of Conformity 83
16 Revision History 84

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1 Preliminary Notes
1.1 Proprietary Notice
The information in this document is proprietary to Güralp Systems Limited and may
be copied or distributed for educational and academic purposes but may not be used
commercially without permission.
Whilst every effort is made to ensure the accuracy, completeness and usefulness of
the information in the document, neither Güralp Systems Limited nor any employee
assumes responsibility or is liable for any incidental or consequential damages
resulting from the use of this document.
1.2 Cautions and Notes
Cautions and notes are displayed and defined as follows:
1.3 Manuals and Software
All manuals and software referred to in this document are available from the Güralp
Systems website: www.guralp.com unless otherwise stated.
1.4 Conventions
Throughout this manual, examples are given of command-line interactions. In these
examples, a fixed-width typeface will be used:
Example of the fixed-width typeface used.
Commands that you are required to type will be shown in bold:
Example of the fixed-width, bold typeface.
Where data that you type may vary depending on your individual configuration, such
as parameters to commands, these data are additionally shown in italics:
Example of the fixed-width, bold, italic typeface.
Putting these together into a single example:
System prompt: user input with variable parameters
Caution: A yellow triangle indicates a chance of damage to or failure of the
equipment if the caution is not heeded.
Note: A blue circle indicates a procedural or advisory note.

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2 System Overview
Thank-you for purchasing a Güralp Minimus2 digitiser.
This section describes the key components of a Minimus2 system. The Minimus2 unit
is the main, standard product in the system; other components and accessories are
optional and can be purchased separately. Please check your order confirmation to
see which components were purchased with your system.
The Minimus2 has four fully-featured analogue input channels.
2.1 Key features
•24-bit, four-channel digitiser with nominal 2.44 µV/count sensitivity.
•Compact form, measuring just 134 ×99 ×45 mm and weighing just 0.6 kg.
•Compatible with all analogue seismic sensors with a voltage output.
•Simultaneously accommodates one triaxial sensor(s), one infra-sound
sensor(s).
•Supports automatic Identification of IP addresses via Güralp Discovery
software and a cloud-based or organisational registry server.
•Remote instrument and data management via Discovery.
•Bluetooth Android app for installation integrity checking.
•Low-latency mode for Earthquake Early Warning (< 40 ms).
•Hot-swappable data storage with dual redundant microSD cards.
•GNSS time-synchronisation, compatible with Navstar (GPS), GLONASS, Galileo
and BeiDou constellations.
2.2 Typical applications
•Earthquake Early Warning systems.
•Volcanology.
•Multi-scale seismic networks.
•Structural health monitoring.
•Hydrocarbon exploration.
•Permanent reservoir monitoring.
•Induced seismicity detection.
•Explosion monitoring.

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3 System description
3.1 Güralp Minimus2 digitiser
The Güralp Minimus2 is a combined digitiser and advanced communications unit.
The Minimus2 acquires data from – and allows direct control (where appropriate) of –
connected analogue instruments ( e.g. Güralp Fortis, 3-series, 5-series, 40T and 6T
sensors) and digital instruments ( e.g. the Güralp Certis).
When used with newer version of Güralp 3T instruments and the Certis Instrument,
the digital serial connection available on the 26-way instrument connector is used to
convey additional state of health information as well as calibration and response
information.
3.1.1 LED indicator
The Minimus2 has an LED indicator on the upper surface, which provides status and
configuration information.
•
White: This occurs from power-up until software starts
•
•
Three flashes followed by a pause, then repeat.
•Each flash is either Red or Green
•First Flash – Internal SD card good and recordings (Green)
•Second Flash – External Removable SD card is good and recording (Green)
•Third Flash - GPS Time lock is good (Green)
•
1 blue flash: a trigger event has been detected.
3.1.2 Bluetooth connectivity
The Minimus2 features Bluetooth connectivity, allowing sensor and state-of-health
data to be monitored using the Güralp GüVü app (see section 3.4 Error! Reference
source not found.on page 14) on an Android mobile phone or tablet.
The Bluetooth can be disabled via software to save processor usage but the hardware
module cannot be switched off. BLE (Bluetooth Low Energy) technology is used to

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minimise the power requirement. The Bluetooth transmitter/receiver is in permanent
standby mode and always ready to receive a connection from a phone or tablet.
See Chapter 6.4 on page 58 for further details on connecting to the Minimus2 and its
attached sensors using a phone or tablet.
3.1.3 Data storage
The Minimus2 uses microSD (non-volatile) memory technology to store seismic data
locally. The Minimus2 features two such microSD cards in order to provide
redundancy; this helps to protect the recorded data in the unlikely event of any
corruption or problem with the memory cards. One card is internal and cannot be
removed by the customer; the other is hot-swappable and easily accessible without
any technical knowledge.
The Minimus2 is supplied with two microSD cards that are of equal storage capacity
( e.g. two 64 GB cards).
Güralp recommends the use of industrial-grade SD cards
3.1.3.1 Primary (hot-swappable) microSD card – new style
The upper surface of the Minimus2 has a waterproof screw-in card-holder that is
sealed by an O-ring.
To insert or replace a microSD card, proceed as follows:
1. Rotate the card-holder in an anti-clockwise direction, unscrewing it from the
body of the digitiser.

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2. The microSD card is accessible via the slot in the side of the card-holder. Push
the card in gently and then release the pressure: the card will spring outwards
a little. It can now be grasped and withdrawn.
3. To insert a new card, line it up with the slot as shown and push it gently into
place. Once you feel the spring pressure, continue pushing until more
resistance is felt and then release the pressure: the card will lock into place.
4. Finally, replace the cap and rotate clockwise until hand-tight. Do not over-
tighten and do not use tools.
3.1.3.2 Internal (back-up) microSD card
The second microSD card is factory-installed in a slot inside the unit.
3.1.4 Web interface
The Minimus2 contains on-board firmware that presents monitoring and
configuration interfaces. These are accessible through Güralp’s Discovery software
(see section 3.3 Error! Reference source not found.on page 13) or, with the built-in web
server, via Discovery's browser interface or any standards-conformant web browser.
The Discovery interface allows a number of instrument monitoring, control and
configuration options:
•Sensor readings and instrument State-of-Health
•Network configuration and authentication
•Sensor, timing, and station configuration/information
•Remote data-streaming configuration
•Local data-storage configuration
Caution: The card holder connects electrically to the Minimus2 via
a series of slip-rings which ride on metal fingers in the main body
of the digitiser:
It is very important that the slip-rings and the metal finger-
contacts do not become damaged or tarnished. Take care not to
touch either part. If a Minimus2 has had its card-holder removed,
do not leave it exposed to the elements. If a card-holder is to be
transported when it is not installed in a Minimus2, enclose it in a
protective bag or covering so that it cannot be scratched or
contaminated.
Note: In order to ensure data integrity and security, Güralp only
recommends the use of the supplied industrial-grade microSD cards.
Caution: The internal microSD card is not accessible by the user. Attempts
to remove or replace it will void the warranty.

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Please refer to Chapter 4.3 on page 17 for full usage instructions.
3.2 Accessory package
3.2.1 Ethernet cable
The Ethernet connector allows use of 10BASE-T, 100BASE-T networks. The cable that
connects to the Minimus2 has a metal cover which is IP68-rated and ensures
consistent connections in harsh installation environments. At the other end of the
blue Ethernet cable, there is a standard 8P8C modular jack (often incorrectly called an
RJ45) for attachment to all common networking devices ( e.g. PC, laptop, router,
switch, modem etc.).
Please see section 11.1 on page 65 for the pin-out and further details.
3.2.2 Compact GNSS receiver and cable
The Minimus2 is supplied with a new-generation compact GNSS receiver with an in-
built antenna that supports the GPS (Navstar), GLONASS, BeiDou and Galileo satellite
constellations.
The receiver comes with a black RS-422 cable that has an over-moulded 14-way
LEMO connector. LEMO connectors use an innovative latching mechanism which is
different to the bayonet connectors used elsewhere. To mate, simply line up the red
marks – one on the chassis and one on the free connector – and gently push the
connector into place until they latch together with a click. To disconnect (un-mate),
grasp the outer sleeve of the connector and pull gently.
Please see section 11.3 on page 67 for pin-out details.
3.2.3 Power cable
The Minimus2 comes with a dedicated power cable with a standard military-
specification bayonet connector on one end and bare ends at the other. Two pins are
employed to carry power. The second pair of pins carry a serial port. When used in
conjunction with a Güralp Power Pack Module, these carry information about charge
status, solar panel operation, battery capacity etc.
Please see section 11.2 on page 65 for the pin-out details.
Caution: Do not twist the connector or use any tools.
Note: The does not use a grey/blue combined power/data cable, as used
with many other Güralp products.

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3.2.4 Diagnostic GNSS to Serial cable adapter
The Minimus2 comes with an adapter to connect the GNSS LEMO connector to a
female nine-pin D-subminiature connector (DE9f), which can be used with a standard
serial port to allow diagnosis and debugging of the using a serial terminal emulator
(see section 7 on page 60).
A serial-to-USB converter (not supplied) may need to be used to connect to PCs or
laptops that don’t have a nine-pin serial connector. Please see section 11.3 on page for
full pin-out details.
Caution: We recommend fitting an in-line 3.5 A anti-surge fuse in the
positive power lead to protect the external wiring of the installation.
Note: This facility should rarely be required. It is primarily intended for use
by the Güralp Support Team to help diagnose any problems with the
Minimus2 that may be experienced by the user.

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3.3 Güralp Discovery software
Güralp Discovery is a software application for seismometer configuration and control,
state-of-health monitoring, and waveform viewing and acquisition.
An important benefit of Discovery is that it allows the user to identify the
instruments’ IP addresses on a LAN or via a cloud-based or organisational registry
server without the need for static IP addresses at the stations.
Discovery also provides simple, convenient instrument and data management with
access to hardware State-of-Health (SoH), data streaming; GNSS location; response
and calibration data.
Discovery can download Minimus2 firmware from the Internet and remotely install it
onto any connected digitisers.

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3.4 Güralp GüVü Android and iOS app
For added confidence during deployments in the field, Güralp GüVü, a Bluetooth App,
displays waveforms, orientation, temperature and humidity data for instant checking
of installation integrity.
Please refer to Chapter 6 on page 57 for installation and usage instructions.

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4 Getting started
4.1 System set-up
Güralp highly recommends exploring and gaining familiarity with the inside your lab
before installation in an outdoors environment.
A typical set-up for the connected to an analogue sensor.
Power up the using a power supply with a DC output of between 10 and 36 Volts. We
recommend fitting an in-line 3.5 A anti-surge fuse in the positive power lead to
protect the external wiring of the installation. The will, in turn, provide power to all
connected instruments. Alternatively, the system can be powered by POE (Power over
ethernet).
If the Minimus2 is directly connected to a laptop or PC using the blue Ethernet cable,
make sure that the laptop or PC is configured to obtain an IP address automatically.
More details on how to correctly configure the connection using APIPA (Automatic
Private IP Addressing) are in section 14 on page 80.
4.2 Güralp Discovery software installation
Discovery is a convenient way to identify a device without having to know its IP
address. It allows easy access to the WEB configuration page as well as live
waveforms, and to control and configure the Minimus2 and connected sensors.
Visit www.guralp.com/sw/download-discovery.shtml for links for all available
platforms (currently Windows 32-bit and 64-bit, macOS 64-bit and Linux 64-bit).
Download the installer appropriate for your architecture and operating system, run
the installer and follow the instructions on screen. (Full details of installation and
upgrading are in section 4.2 on page 15.)
Under Windows, the first time that you start Discovery, Windows may ask you to
specify how you wish Discovery to interact with the Windows Firewall. Because
Discovery requires network communication in order to function, it is important that
allow access.
Caution: Observe the correct polarity when connecting the power supply.
The red lead (from pin B) must be connected to the positive terminal,
typically labelled “+”, and the black lead (from pin A) must be connected to
the negative terminal, typically labelled “-”. An incorrect connection risks
destroying the digitiser, the power supply and any connected instruments.
Note: Windows users may have to reconfigure the Windows FireWall in
order to allow Discovery to communicate properly. Please see section Error!
Reference source not found.on page Error! Bookmark not defined. for full
details. Brief instructions are below.

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The Discovery software ‘looks’ on the local network for any connected Güralp devices.
These are displayed as shown below:
Any device on the same subnet will be displayed. The protocol uses a ‘broadcast’ UDP
packet to request a response from connected systems. This will likely not penetrate
routers, firewalls etc unless expressly permitted.
However, any device on a local ethernet hub or switch should respond. This allows
connection without using or typing specific IP addresses.
In an office environment, a local DHCP server will likely offer an address to any
connected device. Güralp digitisers have DHCP enabled by default so making
connection to the network trivial. Discovery will display the device as above without
any worry about addresses.
You can choose which information is shown for each device in the main window. You
can select which columns to display – and hide unwanted ones – by clicking on
"Show” from the "View" menu.
The “Status” column is composed of three icons that represent the Minimus2
connectivity status (whether device is reachable/active or not), timing status (GNSS
or PTP) and storage status (primary/secondary) respectively.

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Hovering the mouse over any of these three icons will display tool-tips giving a brief
description of the status including, for the timing indicator, details of which timing
subsystems are operating:
Within Discovery, internal and connected sensors are referred to as follows:
4.3 Viewing waveforms and system state-of-health
Waveform data recorded by the ’ internal sensors and other connected sensors can be
viewed using several methods, which are described in the following sections.
4.3.1 Using Discovery’s “Live View” window
4.3.1.1 Main features
Discovery offers a versatile live waveform/data viewer. To open the Viewer, in
Discovery’s main window, select an instrument and, from the View tab in the toolbar,
select “Live View”.
The menu will then present three options for data streaming:
•GDI and GCF channels
•GDI only
•GCF only
The GCF option uses the Scream! Protocol to stream data in GCF packets of, typically,
250, 500 or 1,000 samples. The GDI protocol streams data sample-by-sample and also
allows the sending of each instrument's calibration parameters so that data can be
expressed in terms of physical units rather than digitiser counts.
Güralp recommends using the “GDI only” option for waveform viewing. Metadata
(including Calibration) is automatically sent with a stream. The display is thus shown
in real units – not just counts.
The main features of – and the key buttons within – the Live View window are
shown in the following screen-shot. Basic amplitude and time zoom functions are
given in the Window zoom controls panel and streams can be easily added to or
removed from the window by using the check-boxes in the left panel.

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The channels are divided in groups with different hierarchical importance. The most
important are the velocity/acceleration channels with higher sample rates: these
belong to group 1. The least important belong to group 6, which includes humidity,
temperature, clock diagnostics etc . When the live view is launched, only the channels
in group 1 are selected. It is possible to change this setting by selecting a different
group number from the “Select group up to” box at the bottom of the channel list.
When only few channels are selected for viewing, the channel name labels also show
data statistics, including the maximum, minimum and average amplitudes in
physical units.
If too many channels are in view for this information to be visible, you can left-click
on a label and the label and trace will then expand to half the height of the screen,
revealing these statistics. The other channels will be compressed into the remaining
space. Another left-click on the same channel will return the window to normal.
Alternatively, a left-click on a different channel will shrink the original one and
expand the newly-selected one.
By selecting and dragging the mouse over a window of waveform data, the viewer
will display similar statistics for the data within the selected window. When a
window of data is selected, use the key to subtract the ADC offset from the
maximum, minimum and average values. Use the key to calculate the integral
of the selected data. By right-clicking on the window, you can perform advanced
analysis on the data, including plotting power spectral density graphs (PSDs),
spectrograms and discrete Fourier transforms (DFTs), as shown below:

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4.3.1.2 Window control short-cuts
You can change the display of the waveforms with based on a combination of
keystrokes and mouse-wheel scrolling (or track- / touch-pad scrolling on a laptop).
These commands are shown in the table below:
Command
Window control
Amplitude control
Increase/decrease amplitude of all traces
+ hover cursor over channel label
Increase/decrease amplitude of individual
trace
+ + hover cursor over channel
label
Shift individual trace offset up/down
Time control
+
Pan time-scale right/left
+
Zoom time-scale in/out
Trace focus
on trace label
Focus on individual trace
Trace selection
+ hover cursor over on individual
trace / trace label
Remove / de-select trace from Viewer
window
Details control
+ hover cursor over on individual
trace / trace label
Reset the maximum and minimum values to
the average value of the selected data
4.3.1.3 GDI connection settings
The GDI protocol allows a receiver, such as Discovery, to select which channels to
receive by use of a “channel subscription list”. This feature can be useful in cases
where the connection between Minimus2 and Discovery has limited bandwidth. To
subscribe to specific channels, right-click on a digitiser in Discovery’s main window
and select “GDI Configuration” from the context menu.
The resulting window has two very similar tabs. The “Subscription configuration” tab
refers to channels selected for transmission and the “Storage configuration” tab
affects which channels are selected for recording.
Click on the button to connect to the GDI server.
By default, Discovery subscribes to all channels. To alter this behaviour, change the
radio-button from “Automatically subscribe to all available channels” to “Use
subscription list”. In subscription list mode, the channels in the list on the left-hand

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side are those to which Discovery subscribes. All available channels are listed on the
right-hand side.
Channels can be moved between lists – i.e. switched between being subscribed and
being unsubscribed – by using the arrow buttons on the middle:
Subscribe to all channels shown in the Available channels list
Subscribe to all selected channels in the Available channels list
Unsubscribe from all selected channels in the Subscribed channels
list
Unsubscribe from all channels in the Subscribed channels list
4.3.1.4 Backfill from microSD card
Gaps in the waveforms due to network disconnections can be backfilled by
requesting missing data to the local storage.
In the Discovery GDI “Live View”, highlight the portion of data including the gap,
right-click and select “Request backfill”.
The gaps are backfilled automatically for all the streams selected, if the requested
data is available in the microSD card.
4.3.2 Using Scream!
Data from the Minimus2 and attached sensors can also be viewed and analysed using
Güralp's Scream! Software.
For full usage information on Scream!, please refer to the on-line Güralp manual
MAN-SWA-0001.
In Scream!’s Network Control window, add a UDP or TCP Server using the address
reported under “LAN Address” in Discovery’s main window (as described in section
Error! Reference source not found.on page Error! Bookmark not defined.).
Right-click on the newly-added server and select GCFSEND:B (or Connect) from the
context menu. This sends a command to the Minimus2 to start data transmission.
Once the GCFSEND:B (or Connect) command has been issued, the instruments and
their associated streams should begin to appear in Scream!’s main window.