Geokon 8020-42CPR Manuale utente

Installation Instructions

Model 8020-42CPR

Single Coil Autoresonant Adapter

4-20Ma Output

No part of this instruction manual may be reproduced, by any means, without the written consent of Geokon, Inc.

The information contained herein is believed to be accurate and reliable. However, Geokon, Inc. assumes no responsibility for

errors, omissions, or misinterpretation. The information herein is subject to change without notification.

(Rev F, 08/23/2018)

Warranty Statement

Geokon, Inc. warrants its products to be free of defects in materials and workmanship, under

normal use and service for a period of 13 months from date of purchase. If the unit should

malfunction, it must be returned to the factory for evaluation, freight prepaid. Upon examination

by Geokon, if the unit is found to be defective, it will be repaired or replaced at no charge.

However, the WARRANTY is VOID if the unit shows evidence of having been tampered with

or shows evidence of being damaged as a result of excessive corrosion or current, heat, moisture

or vibration, improper specification, misapplication, misuse or other operating conditions outside

of Geokon's control. Components which wear or which are damaged by misuse are not

warranted. This includes fuses and batteries.

Geokon manufactures scientific instruments whose misuse is potentially dangerous. The

instruments are intended to be installed and used only by qualified personnel. There are no

warranties except as stated herein. There are no other warranties, expressed or implied, including

but not limited to the implied warranties of merchantability and of fitness for a particular

purpose. Geokon, Inc. is not responsible for any damages or losses caused to other equipment,

whether direct, indirect, incidental, special or consequential which the purchaser may experience

as a result of the installation or use of the product. The buyer's sole remedy for any breach of this

agreement by Geokon, Inc. or any breach of any warranty by Geokon, Inc. shall not exceed the

purchase price paid by the purchaser to Geokon, Inc. for the unit or units, or equipment directly

affected by such breach. Under no circumstances will Geokon reimburse the claimant for loss

incurred in removing and/or reinstalling equipment.

Every precaution for accuracy has been taken in the preparation of manuals and/or software,

however, Geokon, Inc. neither assumes responsibility for any omissions or errors that may

appear nor assumes liability for any damages or losses that result from the use of the products in

accordance with the information contained in the manual or software.

TABLE of CONTENTS

1. INTRODUCTION .................................................................................................................................................. 1

2. CONNECTIONS..................................................................................................................................................... 2

3. CONFIGURATIONS ............................................................................................................................................. 3

3.1 MICRO-10 DATALOGGER .................................................................................................................................... 3

3.2 GENERIC DATALOGGER CONFIGURATION........................................................................................................... 3

3.3. STAND ALONE CONFIGURATION ........................................................................................................................ 4

6. OUTPUT TO DIGITS CONVERSION................................................................................................................ 5

APPENDIX A. SPECIFICATIONS.......................................................................................................................... 6

FIGURES

FIGURE 1-BLOCK DIAGRAM......................................................................................................................................... 1

FIGURE 2-INTERNAL JUMPER SETTINGS FOR MICRO-10 CONFIGURATION ................................................................... 3

FIGURE 3-INTERNAL JUMPER SETTINGS FOR GENERIC DATALOGGER CONFIGURATION .............................................. 4

FIGURE 4-INTERNAL JUMPER SETTINGS FOR STAND ALONE CONFIGURATION............................................................. 4

TABLES

TABLE 1-CONNECTOR/SIGNAL DESCRIPTION............................................................................................................... 2

TABLE 2-SPECIFICATIONS ............................................................................................................................................ 6

EQUATIONS

EQUATION 1-CONVERT 4-20MAOUTPUT TO DIGITS.................................................................................................... 5

LPF

φ2

VCO

Instrumentation

Amplifier

and

Schmitt Trigger

Phase Comparator

Output Buffer

VW Gage

Coil

Microprocessor

V+

1. INTRODUCTION

The Geokon 8020-42CPR is a device that allows single coil vibrating wire gages to be driven in

the “Autoresonant” mode, instead of the standard “Pluck and Read” mode, resulting in a greater

dynamic range (up to 20Hz). The benefits of Autoresonant vs. Pluck and Read topologies are

many, including greater reading stability and wider dynamic bandwidth. In addition, since there

is no asynchronous swept frequency or pulse pluck excitation to interfere with the vibrating wire

signal, there is the ability to read the gage frequency with a general-purpose frequency counter or

low cost datalogger, instead of a complex dedicated readout device or datalogger. In addition to

the gage frequency output, the 8020-42CPR also provides two 4-20mA signals that are

proportional to “digits” (frequency²). These 4-20mA outputs are factory set for the range of 2250

digits (1500Hz – 20mA) to 12250 digits (3500Hz - 4mA), but may be adjusted for other ranges.

One of the 4-20mA outputs is a non-isolated current source (I_out, / I_out). The other 4-20mA

output (LOOP_+, LOOP_-) is a current sink designed to be used in applications that require an

isolated controller. Typically, the 4-20mA output is adjusted to cover the full range span of a

single transducer.

Historically, autoresonant vibrating wire gages have employed two coils. The first is the

Transmit (excitation) coil that provides a phase synchronous pulse (pluck) to maintain

oscillation, while the second is the Receive (reading) coil that recovers the vibrating wire signal.

The two-coil approach, while dependable, adds to the cost and imposes a considerable

mechanical limitation to the design and construction of the gage. Since the SCA is designed to

operate as a “transceiver” using only one coil, these limitations are eliminated while providing

the benefits of the autoresonant mode.

Figure 1 - Block Diagram

Frequency

Output

Enable

PLL_OUT

VCO_HOLD

T/R

Switch

2. CONNECTIONS

Connector

Position

Signal

Name

Signal

Description

Type Level (typ.)

1 FOUT Vibrating Wire Gage Frequency Output 5Vpp

2 FOUT_ATT

Vibrating Wire Gage Frequency - Attenuated Output 200mVpp

3 LOOP+ Isolated current loop + input (loop power) Power +10 to +30VDC

4 LOOP- Isolated current loop output Output Load dependent

5 DAS GND Power ground for 24V option Ground 0V

6 +12V +12V Power Supply input Power 6-15VDC

7 GND Ground Power 0V

8 /I_OUT Ground return for 4-20mA signal Power 0V

9 I_OUT 4-20mA source Output 4-20mA

10 C+ VW coil + Input 1mVpp

11 C- VW coil - Input 1mVpp

12 CR10EX Excitation (Micro-10 configuration) Input TTL/CMOS (EX)

13 CR10EN Enable (Micro-10 configuration) Input TTL/CMOS (C1.C7)

14 CR10CLK

Clock (Micro-10 configuration)

Enable (Generic Datalogger configuration)

Input TTL/CMOS (C8)

15 GND Ground Ground 0V

Table 1 - Connector/Signal Description

NOTE: Because the 8020-42 requires each vibrating wire gage to have its own pair of twisted

leads, the 8020-42 is not compatible with Geokon models 4900 (VW Load Cell) and 4350-3

(Biaxial Stressmeter).

3. CONFIGURATIONS

3.1 Micro-10 Datalogger

The 8020-42CPR can be incorporated as the vibrating wire interface in a Micro-10 Datalogger

system, taking the place of the Campbell Scientific Inc. AVW-1. In order to configure the 8020-

42CPR for the Micro-10 Datalogger, internal jumpers JP1, JP2 and JP3 must be set across pins

one and two. Remove the cover of the 8020-42 and set the jumpers:

JP1 JP2 JP3

Figure 2 - Internal Jumper Settings for Micro-10 Configuration

Between readings, the 8020-42CPR will be “asleep”, drawing approximately 20µA from the 12V

system battery.

When it is time to take a reading, the datalogger will set C1..C7 (CR10EN) high in order to

enable the respective multiplexer, and the individual channels are clocked by pulsing C8

(CR10CLK) high.

When “CR10EN” and “CR10CLK” are both high, the 8020-42CPR will wake up and wait for

the swept frequency excitation signal to appear at EX. The 8020-42CPR will track and apply this

swept frequency to the VW gage. Once the swept frequency is complete, the 8020-42CPR will

lock onto the returned VW signal and maintain excitation by applying one excitation pulse for

every 16 cycles of VW frequency. The VW frequency is provided as both a 200mv(pp) signal at

FOUT_ATT (connector position two), and as a 5v(pp) 50Ωoutput at FOUT (connector position

one).

It is helpful to add a small amount of delay ( ≈0.5 Sec. ) from the time that the swept frequency

excitation ends and the time that the reading is taken. MultiLogger software, ver. 1.4.0 and above

provides this delay when selecting a gage type that has the letters sca included within it, i.e.,

4500sca, 4700sca etc.

3.2 Generic Datalogger Configuration

The 8020-42CPR can be incorporated as the vibrating wire interface for any datalogger that is

capable of reading a frequency input or a 4-20mA current input and has the ability to output a

single 5V CMOS level control signal. In order to configure the 8020-42CPR for a generic

Datalogger, internal jumpers JP1 and JP3 must be set across pins one and two, while JP2 is set

across pins two and three. Remove the cover of the 8020-42CPR and set the jumpers:

Pin 1

Pin 2

Pin 3

JP1 JP2 JP3

Figure 3 - Internal Jumper Settings for Generic Datalogger Configuration

Between readings, the 8020-42CPR will be “asleep”, drawing approximately 20µA from the 12V

system battery.

When it is time to take a reading, the datalogger will set its control signal, which should be

connected to CR10CLK, high. When CR10CLK goes high, the 8020-42CPR will generate a 400-

4500 Hz swept frequency pluck in order to excite the VW gage. As with the Micro-10

configuration, once the swept frequency is complete, the 8020-42CPR will lock onto the returned

VW signal and maintain excitation by applying one excitation pulse for every 16 cycles of VW

frequency.

The 8020-42CPR will provide continuous VW frequency output until the CR10CLK control line

is brought low. At this time, the 8020-42CPR will go back to sleep

3.3. Stand Alone Configuration

When configured in the Stand Alone mode, the 8020-42CPR will provide continuous excitation

and frequency output from a single Vibrating Wire gage. All that is needed is a 12V (nominal)

voltage source and a frequency counter to read the VW frequency. In order to configure the

8020-42CPR for Stand Alone mode, internal jumpers JP1, JP2 and JP3 must be set across pins

two and three. Remove the cover of the 8020-42CPR and set the jumpers:

JP1 JP2 JP3

Figure 4 - Internal Jumper Settings for Stand Alone Configuration

Pin 1

Pin 2

Pin 3

Pin 1

Pin 2

Pin 3

6. OUTPUT TO DIGITS CONVERSION

Use the following formula to convert the 4-20mA output signal to “Digits”:

Digits = 12250 - [625 x (mA-4)]

Equation 1 - Convert 4-20mA Output to Digits

Where;

mA = 8020-42CPR 4-20mA output signal

For example:

If the 8020-42CPR is outputting a 4-20mA current of 12mA then:

Digits = 12250 – [625 x (12 – 4)]

Digits = 12250 – [625 x 8]

Digits = 12250 – 5000

Digits = 7250

APPENDIX A. SPECIFICATIONS

POWER

Power Requirements: 6-15 VDC (12V nominal)

Current Consumption:

Sleep: 30 µA (max.), 20µA (typ.)

Plucking: 50 mA peak

PLL locked: 30 mA (max.), 22 mA (typ.)

50 mA (max) with 4-20mA

Iout

PLL Capture Range: 1200 – 4000 Hz

PLL Lock Range: 1150 – 4500 Hz

Internally Generated Fsweep:

Frequency (start): 400 Hz

Frequency (end): 4500 Hz

Sweep Duration: 750 mSec

Sweep Shape: Linear

Frequency Outputs:

FOUT_ATT: 200mVpp 1kΩAC coupled

FOUT: 5Vpp 50ΩAC coupled

Control Inputs:

CR10EN: 5V CMOS

CR10CLK: 5V CMOS

EX: 5V CMOS: VW excitation

ENVIRONMENTAL

Temperature range: 0 - 70 °C

Table 2 - Specifications

Indice

Altri manuali Geokon Adattatore

Geokon

Geokon 8020-42 Manuale utente

Manuali Adattatore popolari di altre marche

PCB Piezotronics

PCB Piezotronics 090B274 Manuale utente

Auvidea

Auvidea J20 Manuale del prodotto

Gossen MetraWatt

Gossen MetraWatt AT3-III E Manuale utente

Akribis

Akribis ITF-21-BISS-MIT Manuale utente

Tenda

Tenda W54U Manuale utente

ROHO

ROHO AGILITY Manuale utente

PROLiNK

PROLiNK WN2001 Manuale utente

Hawking

Hawking HUF2 Manuale utente

Airlink101

Airlink101 AWLC4030 Manuale utente

NETGEAR

NETGEAR XAV101v1 - Powerline AV Ethernet Adapter Manuale utente

Philips

Philips SWA4554S/10 Manuale utente

JVC

JVC TS-C9D2B Manuale di istruzioni

NETGEAR

NETGEAR A6100 Manuale utente

D-Link

D-Link DWA-121 Manuale utente

Philips

Philips SWA2037 Manuale utente

Basalte

Basalte 0610-20 Manuale utente

Yealink

Yealink EHS40 Manuale utente

Balluff

Balluff BIC 1B0-IT1A7-Q40KFU-SM4A4A Manuale utente