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 ports 10. Appendix 3 – Güralp Discovery installation 11. Appendix 4 – Connector pin-outs 12. Revision History

Section Index: 4.1. System set-up 4.2. Güralp Discovery software installation 4.3. Viewing waveforms and system state-of-health

Chapter 4. Getting started

4.1 System set-up

Güralp highly recommends exploring and gaining familiarity with the Minimus inside your lab before installation in an outdoors environment.

A typical set-up for the Minimus connected to an analogue sensor (including an optional digital Radian Post-hole instrument) is shown in the figure below.

Typical system set-up configuration for a Radian Post-hole system

To get started, connect the cables as shown in the figure above and as described in section 3.2 (and, optionally, section 4.3 of the Radian manual, MAN‑RAD‑0001).

Power up the Minimus using a power supply with a DC output of between 10 and 36 Volts. This will, in turn, provide power to all connected instruments.

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.

4.2 Güralp Discovery software installation

To view live waveforms, and to control and configure the Minimus and connected sensors, you will need to use Güralp Discovery software. Visit for download links for all available platforms (currently Windows 32-bit and 64-bit, iOS 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 Appendix 2: section 10.)

Note: Windows users may have to reconfigure the Windows FireWall in order to allow Discovery to communicate properly. Please see section 10.4 for full details. Brief instructions are below.

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 you understand the options available.

The following screen is displayed:

The screen provides three check-boxes which indicate whether Discovery can communicate with networked devices in the “Domain” profile, the “Private” profile or the “Public” profile. (Profiles are also known as “network locations”.)

The “Domain” profile applies to networks where the host system can authenticate to a domain controller. The “Private” profile is a user-assigned profile and is used to designate private or home networks. The default profile is the “Public” profile, which is used to designate public networks such as Wi-Fi hotspots at coffee shops, airports, and other locations.

For a more complete discussion of this topic, please see or your Windows documentation.

Once you have specified your firewall preferences, Discovery displays a main window which shows both locally and remotely connected instruments. If you close this main window, Discovery will quit.

Discovery will initially “listen” for connected instruments on your local network. This mode can be refreshed by clicking the “Scan Locally” button or by pressing the short-cut keys +.

Key features of the main window of Discovery

Note: Make sure that the DHCP is enabled. It can be set from the Network Connections properties.

Within Discovery, instruments are referred to as follows:

4.3 Viewing waveforms and system state-of-health

Waveform data recorded by the Minimus’ internal sensors and other connected sensors can be viewed using several methods, which are described below.

4.3.1 Using Discovery’s “Live View” window 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:

The GCF option uses the Scream! Protocol to stream data in packets of, typically, 250, 500 or 1,000 samples. The GDI protocol streams data sample-by-sample and also allows sending of instrument 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.

The main features of – and the key buttons within – the Viewer window are shown in the screen-shot below. 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 Waveform viewer panel.

Main features of the “Live View” function of Discovery

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 group is group 6, which includes humidity, temperature, clock, 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 highlighted in the picture below.

When only few channels are selected for viewing, the channel name labels include data statistics including the maximum, minimum and average amplitudes in physical units. Furthermore, by selecting and dragging a window of waveform data, the viewer will display similar statistics for the data within the selected window. By right-clicking on the window you can perform advanced analysis on the data, including plotting power spectral densities (“PSD”s), spectrograms and discrete Fourier transforms (“DFT”s).

Waveform analysis features

Window control short-cuts

Manipulating the display of waveforms can be carried out using the commands shown below which are based on a combination of keyboard keys and mouse-wheel scrolling (or track- / touch-pad scrolling on a laptop).

These commands are shown in the table below:


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 GDI connection settings

The GDI protocol allows a receiver, such as Discovery, to select which channels to receive by use of a “channels subscription list”. This feature can be useful in cases where the connection between Minimus and Discovery has limited bandwidth. To subscribe to 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.

By default, Discovery subscribes to all channels. This can be controlled by clearing the tick-box “Automatically subscribe to all available channels”. When the box is cleared, the channels list in the left-hand side list are those to which Discovery subscribes. All available channels available channels listed on the right-hand side.

4.3.2 Using Scream!

Data from the Minimus and attached sensors can also be viewed and analysed using Güralp Scream! Software.

For full usage information on Scream!, please refer to Güralp manual MAN‑SWA‑0001 (MAN‑SWA‑0001.pdf">‑SWA‑0001.pdf).

In Scream!’s Network Control window, add a UDP Server using the address reported under “LAN Address” in Discovery’s main window (section 4.2).

LAN Address of connected instruments shown in Discovery

Right-click on the newly-added server and select GCFSEND:B from the context menu. This sends a command to the Minimus to start data transmission. Once the GCFSEND command has been issued, the instruments and their associated streams should begin to appear in Scream!’s main window.

Screen-shot showing streams from the Minimus in Scream!’s main window


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 ports 10. Appendix 3 – Güralp Discovery installation 11. Appendix 4 – Connector pin-outs 12. Revision History