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

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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: 3.1. Güralp Minimus digitiser 3.2. Accessory package 3.3. Güralp Discovery software 3.4. Güralp GüVü Android and iOS app

Chapter 3. System description

3.1 Güralp Minimus digitiser

The Güralp Minimus is a combined digitiser and advanced communications unit. The Minimus acquires data from – and allows direct control of – connected analogue (e.g. Güralp Fortis, 3-series, 40T, 6T sensors) and digital instruments (e.g. the Güralp Radian).

The Güralp Minimus functions as the Surface Interface Unit (SIU) for Radian post-hole instruments in shallow (<100 metres), single-instrument borehole installations. A full description of the operation, control and configuration of the Güralp Radian instrument via the Minimus is not within the scope of this manual; please refer instead to the Radian manual, MAN‑RAD‑0001.

Main external features of the Minimus

3.1.1 MEMS accelerometer

The Minimus digitiser is equipped with a triaxial Micro Electro-Mechanical Systems (MEMS) accelerometer with a measuring range of ±2 g.

The accelerometer’s axes of sensitivity are illustrated in the picture below:

3.1.2 LED indicator

The Minimus has an LED indicator on the upper surface, which provides status and configuration information.

3.1.3 Data storage

The Minimus uses microSD (non-volatile) memory technology to store seismic data locally. The Minimus 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 Minimus is supplied with two microSD cards that are of equal storage capacity (e.g. two 64 GB cards).

3.1.3.1 Primary (removable / hot-swappable) microSD card slot

The upper surface of the Minimus has a waterproof screw-cap that is sealed by an O-ring.

To insert or replace a microSD card, proceed as follows:

Note: Güralp only recommends the use of the supplied industrial-grade microSD cards, in order to ensure data integrity and security.

3.1.3.2 Internal (back-up) microSD card

The second microSD card is factory-installed in a slot inside the Minimus.

Caution: The internal microSD card is not accessible by the user. Attempts to remove or replace it will void the Minimus’ warranty.

3.1.4 Bluetooth connectivity

The Minimus features Bluetooth connectivity, allowing sensor and state-of-health data to be monitored using the Güralp GüVü app (see section 3.4) on an Android mobile phone or tablet.

There is no switch to enable/disable Bluetooth. BLE (Bluetooth Low Energy) technology is used to 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 for further details on connecting to the Minimus and its attached sensors using a phone or tablet.

3.1.5 Firmware

The Minimus contains on-board firmware that presents monitoring and configuration interfaces. These are accessible through Güralp’s Discovery software (see section 3.3) or through the built-in web server, via any standards-conformant web browser.

The web interface allows a number of instrument monitoring, control and configuration options:

Please refer to Chapter 5 for full usage instructions.

Web browser interface of the Minimus’ firmware

3.2 Accessory package

3.2.1 Ethernet cable

The Ethernet connector allows use of 10BASET, 100BASE-Tx or 1000BASE-T networks. The metal gland shell-type connector that connects to the Minimus is IP68-rated and ensures consistent connection 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 90 for pin-out and further details.

3.2.2 Compact GNSS receiver and cable

The Minimus is supplied with a new-generation compact GNSS receiver with an in-built antenna that supports GPS (Navstar), GLONAS and BeiDou satellite constellations.

The receiver comes with an RS422 black cable that has an over-moulded 14-way LEMO connector. The connector uses a push/pull latching mechanism to provide a secure, rugged and durable connection occupying only a small area. To insert the GPS cable, line up the two red marks – one on the chassis and one on the free connector – then firmly push together until the connectors click into place. To disconnect, simply grip the outer sleeve and pull.

Please see section 11.3 on page 92 for pin-out details.

3.2.3 Power cable

The Minimus comes with a dedicated power cable with a standard military-specification bayonet connector on one end and bare ends at the other.

Note: The Minimus does not use a grey/blue combined power/data cable, as used with many other Güralp products.

Please see section 11.2 for pin-out details.

3.2.4 Diagnostic GNSS to Serial cable adapter

The Minimus 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 Minimus using a serial terminal emulator.

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 for full pin-out details.

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 Minimus that may be experienced by the user.

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’ I.P. addresses on a LAN or via a cloud-based registry server without the need for static I.P. address arrangements. Discovery also provides simpler instrument and data management with access to hardware State-of-Health (SoH), data streaming; GNSS location; response and calibration data.

Discovery can download Minimus firmware and remotely install it on any connected Minimus digitisers.

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 for installation and usage instructions.

View of the GüVü app on an Android tablet device

PreviousNext

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