Keynes Controls VibWire-108 User Manual
VibWire-108
Vibrating Wire Sensor Interface Unit
User Manual Version 1.05 - Otcober 2008
Introduction
The following document details the model types, configuration
and operational features for the Keynes Controls VibWire-108
range of vibrating wire sensor interface.
The VibWire-108 units contains 8 x 4 wire sensor inputs and The
sensor interface consists of two inputs, one for the vibrating wire
sensor and the other for temperature/analogue input.
This document shows all the different hardware configurations and
User options available for the operation of the instrument.
All instruments are supplied with on-board frequency display and
a speaker also with or without analogue output ports.
Hardware Options
VibWire-108-RS485 RS 485 serial comms unit
VibWire-108-SDI12 SDI-12 serial comms unit
VibWire-108 Analogue Output
.
Instrument Scanning Operations
The VibWire-108 is a multiplexed instrument and as such scans
each channel before working out the sensor frequency and moving
on to the next channel. Only after all of the sensor inputs are
scanned are the results made available for data transmission across
the various communications networks or analogue output interface.
Configuration
The only time the sensor inputs require any configuration is when
the analogue output channels are to be used. For SDI-12 and
RS485 the sensor inputs operate automatically.
Real-time Operations
The VibWire-108 can be set to operate in real-time mode with the
real-time display operating on a single channel only. This is ideal
for testing and setting up sensors as any adjustment to the sensor is
instantly shown on the display.
Power Consumption
All of the VibWire systems use advanced power management
operations to minimise the power consumption and so make the
instrument ideal for stand-alone remote applications. Power
requirements are:
Power Supply 11-18V DC @ 0.25A
Scanning mode: 70mA aprox 30 seconds / scan
Display mode: 90mA continuous
SDI-12/RS485 network: Waiting for command 20mA continuous
Analog output mode: 25mA continuous
Solar Panels 4.8W cell gives 1 Reading /Hr indefinitely
Photo VibWire-108
Field Operations
There are various VW-108 models available offerings cable free,
GPRS modem, SDI-12/RS-485 serial port communications and
analogue outputs. All instruments no mater the model contain an
on board frequency display, ceramic speaker and User keyboard.
In order to ensure that the VibWire-108 systems operate as reliably
as possible they all contain lightening protection on sensor inputs
and isolated serial ports for digital data transmission.
The VibWire-108 series of instruments support everything needed
to make and report accurate vibrating wire sensor readings and also
to act as local display and diagnostic tool and report data across all
of the most common communication interfaces and data
transmission networks.
Fully Integrated Data Logger
The VibWire-108 has been fully integrated to the Keynes Gateway
data logger and communications interface. The Gateway can act as
a communications interface for connecting the VibWire-108 to
range of cable free networks such as GPRS and ZigBee. The
Gateway also supports USB data stick recording making it ideal for
fixed site recording.
The Gateway also controls the power management for the
VibWire-108 and switches off any third party equipment when not
in use to minimise systems power requirements.
Keynes Controls Reserves the right to make changes without notification. Refer to
the network drawing for details of the electrical connections.
Index
Page No. Description
1 Introduction
Instrument Scanning Operations
Power Consumption
2 Index
3 USB Data Recording
Gateway Settings for USB Data Recording
4 SDI-12 Serial Network Connection
Starting SDI-12 on the VibWire-108
5 RS-485 Serial Network Connections
Starting Data Acqusition Operations on a 485 Network
6 VibWire-108 Serial Port Communications
Command Structure and Operations across an RS-485 Network
Timing Constraints RS-485 / SDI-12 Network
Data Access Time
RS-485/ SDI-12 Commands
7 Start Measurement Commands
Initial Configuration
Table Of Commands SDI12 & RS-485
Communication ports Settings for SDI-12 & RS-485 network
8 Examples Of Using RS-485 / SDI-12 Instructions
Changing the ID Number (address)
ID Number Query
Start Measurements upon distributed instruments upon a network
9 Start Concurrent measurements on a number of distributed instruments
Read values from VibWire-108
Temperature / Current loop Data Format
10 Connection to an analogue data acquisition system
Technical specification - analogue output ports
Theory of operation
Starting Analogue Output Ports
11 Optimising the Analogue Output Settings
Integration to NDACS 6000 Logger
12 Real-time Frequency Display
Loud speaker
Sensor Problems
13 Vibrating Wire Sensor Installation
Lightening Protection
Multiple instrument installation
PCB Jumper Settings
14 Local Cable Free Systems
Local operation under 500 m to Gateway
Configuring the VibWire-108 for Data Transmission
Setting Data Transmission Rates
Setting Sensor Polling Rate
15 Antenna Installation
Typical Antenna solutions for 2.4 GHz Applications, Basic System Installation,
Directional Antenna Systems - External Mounting, Omni-directional antenna - External Mounting
16 Mesh networks, Network Operations
17 User Command Summary
18 GPRS Operations
Terminal Port & Hyperterminal Connection, GPRS Modem Configurations, Data Management
User Display & Speaker Unit
19 Database Operations
Data integrity Operations, Data Summary plots, Global Solutions, Local Systems
GPRS modem specifications
20 Example GPRS network configuration settings
Terminal Port & Hyper-terminal Connection
21 Serial Port to USB Communications
Active Comms Port
22 Serial Port to Ethernet Communication
Technical Specifications
23 Vibrating Wire Sensors
24 Vibrating Wire Sensor Applications
25 Case Study - Bore Hole Pump Control, Stand-alone Weir Control System with Data Logger
3
Add example of USB logging with example
Record data to a usb stick at 1 minute interval using 2 x VibWire108 instruments on an SDI-12 network to the Gateway data
recorder. Make sure the uSB adapter is connected to the Gateway.
Step 1 - Configuring the VibWire-108
There are 2 parameters needed to be set within the VibWire-108
when configuring operation with the Gateway or in fact any other
SDI-12 based device.
Number of Channels to scan (default =8) See page 17
Instrument ID number (0-9) (See Page 17)
Set ID number on the first instrument to 0
Set ID number on the second instrument to 4
Gateway Logger Parameters
Go the USB Data Recording menu options from the Gateway
menu system
1. Baud rate = 9600 (default) no need to adjust
2. MyFile.csv comma separated variable
User defined filename
3. Highest Column = K
For this example setting he Highest column to K represents
11 data values ie the 11th letter in the alphabet.
Column 1 = record number
Column 2 = Date
Column 3 = Time
Columns 4 - 11 representing data values returned from the
VibWire-108 instruments.
See Gateway Manual for full details.
USB Data Recording Applications
The VibWire-108 data can be stored to the USB memory stick
when used in collaboration with an SDI-12 network data recoreder.
The Keynes Gateway supports SDI-12 network and USB data
recording making it ideal for stand-alone permanent data recording
applications.
The Gateway and USB interface are both immersion proof and so
Suitable for operation in the harshest of environments. Should a
site flood then the instrumentation will still operate.
USB Data Recording
Data from a VibWire-108 can be stored directly to USB memory
stick using the Keynes Gateway data recorder with the USB
interface attachment.
Configuring VibWire-108 for USB Data Recording:
1. Set the number of channels to be scanned.
2. Activate the SDI-12 Port (See page 4)
The VibWire-108 only reports data for channels set to be scanned.
The lower the number of scanned channels the faster the instrument
responds and the lower the amount of power need for operations.
3. To store data to the USB data stick via the Gateway Logger
Using the 9 pin serial port on the Gateway and a teriminal program
on a laptop or other suitable programming device, configure the
Gateway to undertake the following operations:
A) Set the sample rate - typically 1 Scan / Min
B) Define the data table for storage for the Frequency &
temperature parameters
C) Assign storage as USB from the Gateway menu.
See
http://keynes-controls.com/2008/Downloads/GatewayManualV102.pdf
For full Gateway manual details.
Gateway Programming Options for USB Data Recording
1 Baud rate 9600 (Default)
2 Filename Prefix MYLOG (Name of file)
3 Highest Column AF (Last column in table)
4 Logging interval (mins) 1 (Data storage rate)
SDI-12 Configuration Parameters
Set the output to be SErAL -- serial port output. This will activate
the data to be sent out across SDI-12 network.
Channel Scanning
The lower the number of channels scanned on the VibWire-108
then the faster the instrument returns results and the lower the
amount of power required for operations.
VibWire-108
USB Flash Drives
1 - 8 Gb storage
Part No.
NP-GAT-USB-01
USB interface for Gateway
SDI-12 Network
Minimum VibWire-108 system
Suitable for USB data recording
Item 3, the highest column is the position in the Gateway internal
data table into which data is stored.
Once the USB adapter is fitted onto the Gateway and the unit is set
to record then information starts to be stored to the USB stick. The
VibWire-108 will be activated from the Gateway and powered off
between scans to save power. To replace the USB stick simply pull
and and swap with another device.
SDI-12 serial data transmitted
Earth
12V DC
12V DC
SDI-12 Serial Network Connection
Figure 7
Starting SDI-12 on the VibWire-108 Instrument Identifier
To activate the analogue output channels on the VibWire-108. Each instrument deployed on the SDI-12 multi-drop network
must have a unique instrument identifier set in order to identify
1. Starting at specific instrument on the network. For the SDI-12 network this
identifier is 0-9.
See Page 8 for details on setting the ID number.
2. Select “Menu In” button
3. Use the Up & Down Keys to select the option “Seral”
“Analg C0d C1d C2d C3d C4d C5d C6d C7d” are the other options available
Once the “Seral” output is selected the “Menu Out” key has to be pressed to confirm this option.
4. The VW-108 will return to the display
and now the SDI-12/RS-485 port for the instrument is now activated.
4
Earth
Earth
Earth
Earth
NPN-4
NPN-3
NPN-4
NPN-3
485 + / SDI-12
485 -
+ 12V
Gnd
The SDI-12 multi-drop network requires only 1 wire to be
connected between instruments for the communication of data.
This ensures that the installation and use of the SDI-12 network
very simple operation. The SDI-12 network has a limited range but
is ideally suited when connecting instruments together within an
enclosure or when systems are deployed locally.
Each instrument can have its own independent power supply but
must have the two dedicated network wires connected as shown
above in Fig 7. A unique instrument identifier has to configured in
order to access data from a dedicated instrument. Any data logger
supporting the SDI-12 network can obtain information from the
VibWire-108-SDI12.
Ensure that a good Earth
connection is made and fitted to
each instrument in order that
the lightening protection
discharge tubes will operate.
SDI-12 data on pin 4
0V or Ground
Pin 4 on each instrument are daisy chained together for SDI-12
operations
Starting Data Acquisition Operation on a 485 Network
To activate the SDI-12/ 485 output channels on the VibWire-108
1. Starting at
2. Select “Menu In” button
3. Use the Up & Down Keys to select the option “SErAL”
“Analg C0d C1d C2d C3d C4d C5d C6d C7d” are the other options available
Once the “SErAL” output is selected the “Menu Out” key has to be pressed to confirm this option.
4. The VW-108 will return to the display
and now the SDI-12/RS-485 port of the instrument are now activated.
Instrument Identifier
Each instrument deployed on the RS-485 multi-drop network must have a unique instrument identifier set in order to identify specific
instrument on the network. For the RS-485 network this identifier is 0-9 and a-z
See Page 8 for details on setting the ID number.
Earth, -RS485, +RS485 lines are connected in common to all units
RS-485 Serial Network Connections
Figure 7
Copyright Keynes Controls 2005- 2006 Release Version 1.06
12V DC
12V DC
RS485 - Common to all instruments
RS485 + Common to all instruments
Earth
Earth
Earth
Earth
NPN-4
NPN-3
NPN-4
NPN-3
485 + / SDI-12
485 -
+ 12V
Gnd
1
4
1 Gnd
2 Power
3 - RS485
4 + RS485 / SDI12
Control Signal Lines
5
VibWire-108 Serial Port Communications
The instructions below detail the operations to follow to operate the VibWire-108 across both the SDI-12 and RS-485 serial networks.
No sensor configuration details need be applied to the VibWire-108 when operating with the cable free transmitter, RS-485 or SDI-12
network. Simply connect the sensors to the interface as shown in Fig 2 and initiate the commands listed below.
Recommended Test
Use a single instrument only when undertaking initial measurements with a VibWire-108 on the RS-485 or SDI-12 network. This
simplifies the software and will speed up the understanding of the command used to obtain data. It is very easy to test the results
measured across the RS-485 and SDI-12 network with the ones shown on-board frequency display of the unit.
The results obtained across the RS-485 and SDI-12 network will be same as those shown on the display for a specified channel.
The default instrument address for a unit straight out of the box is 0
Issue command 0M! to start measurement operations. The VibWire-108 will scan all channels
0D0! returns items of data address data 4d1, data 4d1, data 4d1, data 4d1
Ensure that each instrument used on a network has a unique ID number assigned within its configuration in order to correctly identify
the data that is being recorded.
Command Structure and Operations Across An RS-485 Network
The VibWire-108 uses a command structure across the RS-485 network very similar to that used by the SDI-12 network in order to
simplify the overall system operations. Understanding the control of the instrument on one network be that RS-485 or SDI-12 will make
using the the unit on the other a very simple operation.
The RS-485 and SDI-12 network both operate at the same speed of 1200 baud.
Even though this is a relatively slow rate, as networks go, it is more than adequate for the small amounts of data transmitted by the
instrument.
No break characters are transmitted in an RS-485 command and any sent will be ignored by the instrument.
A short delay of approximately 10 ms is added between a command received by VibWire-108 and its transmission of data since this
delay is used to allow time for the host PC to turn off its transmitter when using soft-negotiation for data flow control operations.
Under normal RS-485 data transmission operations the RTS line on the serial port is used for flow control operations.
Keynes Controls recommends an RS-485 interface with Hardware negotiation is used to control the VibWire-108 across a network.
Timing Constraints RS-485 / SDI-12 Network
There are no timing constraints for the transmission of instructions and receipt of data across an RS-485 network compared to the
operations on and SDI-12 network.
Data Access Time
Typically the VibWire-108 takes 5 seconds to complete the scan of the first sensor and a further 3 seconds for any other sensor
connected to the instrument. The actual response time for the instrument is dependent upon number of sensor fitted and can interrogated
using the
RS-485/ SDI-12 Commands
The commands used by instruments on the SDI-12 and RS485 network are the same
In the following commands 'a' and 'b' are the address of the instrument and can only be integers 0 to 9 or the characters a - z.
where
'ttt' represents a time in seconds (0 to 999 seconds)
'n' or 'nn' represends a number of channels (00 to 99 channels)
\r and \n are the Carrigde Return and Line Feed characters - ASCII 13 and 10.
12 mS
8 mS
SDI-12 Data
Figure 8 shows timing delay used on SDI-12 serial bus
prior to sending data
Page 6
Start Measurement Commands
There are 2 separate commands supported by the VibWire-108 for initiating measurements across an RS-485 network and are named
‘aM!’ and ‘aC!’. Table 1 includes a complete description of the commands used by the VibWire-108
The ‘aM!’ starts a measurement and responds as soon as the data is ready to be transmitted from the instrument. This command returns
all instrument sensor inputs as a string
The ‘aC!’ command starts concurrent operations that are used to initiate measurements upon multiple instruments deployed across the
network. The ‘aC!’ command frees the RS-485 bus so that other devices can operate freely.
Initial Configuration
To setup a multi-instrument RS-485 network the ID number used to select an instrument on the network has to be adjusted from the
default factory settings. It is recommended that each instrument is individually configured before being deployed in order that there is
no confusion within the configuration settings.
Care is to be taken that each instrument to be deployed has a unique ID number to ensure that data is correctly identified.
The initial factory set ID number for each instrument is 0.
Table Of Commands
The following commands are all those supported by the VibWire-108 for use on the SDI-12 nad 485 multi-drop serial networks.
Additional Information
1 Strain gauge data is given as frequency in units (Hz) The RS-485 commands are almost identical in their
2 Temperature data is given in millivolts (0000.0 to 2500.0) format and use to those used on an SDI-12 network.
3 Communication ports Settings for SDI-12 & RS485 network. 1200 baud 8 bit no parity
Description Master VibWire-108 Response
Acknowledge active a! a\r\n
Send ID:
provided to complement SDI-12 protocol
aI! a13KEYNESCOVibWire-1080001\r\n
Part Description assigned by Keynes
Address query
identifies instrument address
and commonly used on single instrument
operations only.
?!
Used to make command set SDI-12
compatible
a\r\n
Where a = number 0 - 9 for SDI-12
0 -9 letters a - z for RS485
A - Z
change Address:
used to change instrument address from
default to new one for network operations
aAb!
a = initial address b = new address
b\r\n
a : b = number 0 - 9 or a - z
Start Measurement
instruct an instrument to make
measurement
aM!
a = address of instrument
example 0M! starts scan for ID 0
a0608\r\n
instrument with address a returns 8 x
vibwire & 8 x temp after 60 seconds
Concurrent measurement:
Used for polling multiple instruments on
a network to start to make readings. This
command frees RS-485 bus for other devices
aC!
start measurement instrument address a
a06016\r\n
initial response only after receipt of instruct and no response when data ready
to be sent.
Send data
data returned
aND! = Vib + Vib + Therm + Therm
and has same format for each command
aD0! aD1! aD2! or aD3!
aD0! = channel 0 and 3 VibWire Sens
aD1! = channel 4 and 7 VibWire Sens
aD2! = channel 0 and 3 Therm/analog
aD3! = channel 4 and 7 Therm/analog
+xxxx.x+xxxx.x+xxxx.x+xxxx.x\r\n
Copyright Keynes Controls 2005- 2006 Release Version 1.06
Page 7
Copyright Keynes Controls 2005- 2006 Release Version 1.06
8
Examples Of Using RS-485/SDI-12 Instructions
The following examples show how to undertake the various tasks needed to setup and make readings across the RS-485 and SDI-12
networks.
The
SDI-12 networks only supports up to 10 instruments with address range: 0 to 9
Changing the ID Number (address)
The following example demonstrates how to change the instrument ID number from the default factory setting 0 to 5.
Use the command ‘aAb’ where a = Start ID b = Final ID
master sends: ‘0A5’ Instrument responds 5\r\n Return New Line (5 representing new ID number)
ID Number Query
This command has been included to remain compatible with the SDI-12 and should be used for used with single instrument operations
only. Useful command when identifying ID numbers for instruments to be deployed on a multi-instrument network.
The example below is to show the ID number of a single instrument
Use the command ‘?!’ .
master sends:: ‘?!’ Instrument responds 3\r\n Return New Line (3 is the ID number)
Start Measurements On Distributed Instruments Upon A Network
The following example shows how to start measurements on instruments with ID numbers 2, 7, and 9 respectively.
For this example the instruments are instructed to start readings one at a time and the network is not freed up until each instrument
responds that the readings are being undertaken.
The instruments will start their measurement operations but will not send data across the network until instructed to do so.
Use the command ‘aM!’ where a = Instrument ID Number
Examples of use.
The following example is based upon a simple application of 3 x VibWire-108 units connected together on a local network. Unit 1 with
address 2 has 4 vibrating wire sensors, Unit 2 with address 7 has 6 sensors connected and finally Unit 3 has only 2 sensors connected.
master sends: ‘2M!’ Instrument responds ‘20144\r\n’ indicated readings available after 60 secs
followed by ‘2\r\n’ when the measurement is completed
7M! ‘70206\r\n’
‘7\r\n’
9M! ‘90082\r\n’
‘9\r\n’
Note. For this command the RS-485 network will not become available until each instrument completes its measurement cycle.
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