Guralp Systems CMG-SAM User Manual

CMG S.A.M & C.R.M

STORAGE & ACQUISITION

MODULE

& COMBINER REPEATER MODULE

OPERATOR’S GUIDE

Operator’s Guide CMG SAM & CMG CRM

DESIGNED AND MANUFACTURED BY:

GÜRALP SYSTEMS LIMITED

3 MIDAS HOUSE
CALLEVA PARK
ALDERMASTON

READING

BERKS, RG7 8EA

ENGLAND

Telephone: [phone] Fax: [phone]

PROPRIETARY NOTICE

The information in this Manual is proprietary to Güralp Systems
Limited and may not be copied or distributed outside the approved
recipient’s organisation without the approval of Güralp Systems
Limited.

Güralp Systems Limited shall not be liable for technical or editorial
errors or omissions made herein; nor for incidental or consequential
damages resulting from the furnishing, performance, or use of this
material.

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Operator’s Guide CMG SAM & CMG CRM

CONTENTS

1.

2.

2.1

2.2

2.3

2.4

2.5

2.6

3.

4.

5.

5.1

5.2

6.

page

Introduction 5

Operating Instructions 6

Power Supply
Front Panel Connectors
Front Panel LED’s
Configuration
Changing SCSI Discs
Flash Memory Upgrade

Digital I/O Interface 17

Microprocessor 18

Data Storage 19

Silicon File
SCSI Disc

Data Transmission Protocol &

6
6
7

8
13
14

19
19

21

Data Block Transfer

7. SAM User Commands 24

8.

Connector Pinouts 26

Flash Memory SAM Connector Pinouts 27

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Operator’s Guide CMG SAM & CMG CRM

1. INTRODUCTION

The Güralp Systems Storage and Acquisition Modules (SAM’s) and Combiner­Repeater Modules (CRMs) are designed to provide the optimum solution for high
performance Seismic Data Acquisition Systems, from a single autonomous sensor, to a
multi-channel, multi-sensor seismic array.

The SAMs and CRMs are available with 2, 4 or 6 input ports, which can each accept
digital inputs from 3-component broadband instruments or digital telemetry links.

The CRM combines data from an array of instruments and outputs it as a single stream
for further transmission. For example, a standard CRM with 2 ports will combine two
3-component sensors plus state of health data sources into one (higher rate) output
stream. The single combined output can then be sent via radio, telephone or digital
telemetry.

The SAM can function in a similar manner as the CRM but includes the ability to store
the combined data on a removable hard disc. The SAM can therefore be used where a
telemetry link is unreliable or impractical. The stored data can be retrieved on, say, a
monthly basis (depending upon the amount of data and disc size). The SAM’s output
port could be used to check an array of remote instruments whilst on site changing SCSI
discs.

As part of the continuing development of all our products, the latest SAM has enhanced
features, a Combine Repeater and Storage Module with dual functionality. This can be
obtained either with or without a backup disc. The new SAM is flash programmable
and can perform a stream synchronisation function, ie. where the SAM is collecting data
from an array of instruments, the timing function for the whole array can be performed
by the SAM unit with a GPS, rather than each individual instrument operating timing
functions independently. Because of this enhancement, the front panel has a different
layout and connector pinouts should be checked in the back of this manual.

The CMG-SAM module writes continuous data to a solid state Silicon File Data Buffer,
and archives data from the silicon file to an internal hard disk. Data is stored on disk in
Güralp Compressed Format (GCF). GCF uses a difference algorithm to express all data
as 32, 16 or 8-bit differences, depending on the dynamic range required for the data
block. GCF reduces baud rates and storage capacities compared to non-compressed
data formats. The basic SAM system includes the Hitachi H8 16 Mhz microprocessor,
2 UARTs, 4 Mb silicon file data buffer and hard disk data storage (9 Gb SCSI as
standard, with optional larger sizes or 2½ inch disc drives).

The output or Aux port means the SAM can download to, and is fully configurable
through a PC serial port. Depending upon the users telemetry link and using Guralps
SCREAM software, the SAM becomes transparent and the user can configure any of the
attached instruments remotely.

To obtain the highest available resolution and noise performance from the digitisers
particular attention has been paid to the design of power supply and isolation of
analogue and digital circuitry (all serial i/o ports are optically isolated).

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P

A

2. OPERATING INSTRUCTIONS

2.1 POWER SUPPLY

As the start-up current of the SCSI disc can be up to 1.5A, the SAM contains an internal
backup battery to buffer the infrequent demand of the disc. This means normal running,
demand is less than 200mA, but can be up to 300mA when recharging the internal
batteries.

2.2 FRONT PANEL CONNECTORS

Input ports

A B C D E F

ux Port

Port A (B, C, D, E, F)

Input port from sensor digitiser.

Aux Port

Output port to PC (direct or via radio/telemetry link).

Power 12V input power supply to SAM.

NOTE

: See the appendix at the back of this manual for the pinouts of each plug.

ower

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A

D

R

A

2.3 FRONT PANEL LED’s

Com Port Status

ux

AM Status

isc Status

ccess

Com Port Status

The data input stream LED’s show that the data is arriving to the port. During
the period of valid data the LED is continuously lit.

Aux
This ‘bi-colour’ LED will turn on green when the system receives the ‘ACK’

character from the block just transmitted (indicating that the data was received
correctly by the PC or SAM); or turn red if the system receives a ‘NACK’ (Not
ACKnowledged) from the last transmitted block.

This LED is turned off when the DM starts transmission of the next block of
data. Thus the time that this lamp is on green gives an indication of the amount
of free time available on the link.

RAM Status

A four element binary “bargraph” display is used to indicate the status of the
silicon file buffer. Green LED’s indicate the smallest binary bits (weight 1, 2,
&3) and red is used for the most significant bits (weight 8). For example, 2
green LED’s indicate

3

/16 full and 1 red LED indicates ½ full.

Disc Status

Another four element binary “bargraph” display to show the relative content of
the SCSI disc, similar to the RAM Status LED’s above. Data are transferred
from the silicon file buffer when it is 15/16th full (all LEDs lit) and data transfer
stops when it is 1/16th full (1st green LED).

Access

This lights red when the SCSI disc is being accessed, ie downloading data from
the silicon buffer.

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