Connecting the VibWire-108 to Campbell CR800 Loggers

Operations

The CR800 & CR850 model data loggers can read information from the VibWire instruments using the SDI-12 serial network. The complete process of reading a signal from a Vibrating wire sensor to the storage within the logger is purely a digital operation. The Campbell logger acts as the SDI-12 Master and the VibWire-108 instruments as SDI-12 slave units. The standard SDI-12 commands shown within  Campbell manuals are compatible to reading information from the VibWire-108 interface. Refer to the product manual for detail son reading data across the SDI-12 port.
CR800 & CR850 connected to SDI-12

All of the sensor inputs and SDI-12 port are gas discharge tube or transorb
protected making the use of the VibWire-108 the desired choice for remote
field applications.

Interface Deployment Options

Several methods for using the VibWire-108-SDI12 and CR800 loggers are
detailed below.
pp652da7df.jpg
SDI-12 data signal  is connected
common to all units
12V DC
12V DC
Gnd
Gnd
SLAVE
SLAVE
Gas Discharge
Tube protection
Download manual at     http://www.keynes-controls.com/vibwire108manual/manualv103.pdf    (6 mB)
Low Power Mode

Connect the VibWire-108 to a solar cell and battery backup unit. Using the internal clock within the instrument the VibWire-108 can wake up, make a scan of the sensors and wait for the CR850 to make a reading then it will power off. This method of deployment will remove the use of the logger as the power source and yet maintains low power operations.
Direct Connection to Logger

Using the Switched 12V output under program control the CR800 logger can power up the VibWire-108 using the internal battery as the power supply, wait for the interface to complete the desired sensor scan, read the information and then power of the unit.
Sensor Input Protection

All of the sensor inputs are protected with individual Gas discharge tubes and
transorbs.

It is important that a good Earth connection is made to the instrument in order that the lightening protection to operate correctly.