Nanometrics TC120-PH1, User Manual

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Chapter 5
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Configuring Your System
Trillium Compact User Guide
16889R5

2014-03-04
31
5.2 Using a Trident Digitizer with a Trillium Compact
Refer to the user guide for your Trident digitizer for complete instructions on using it with a
seismometer. Nanometrics cable 17334-nM (where n is the length of the cable in metres)
can be used to connect a Trillium Compact to a Trident digitizer. See Table 1-1 “List of
cables and accessories” on page 4 for descriptions of these cables.
Following are instructions for configuring your Trident and NaqsServer to work with a Trillium
Compact seismometer.
1. Match the settings on the Configuration tab of Nanometrics UI to those in the following
table.
2. Ensure the NaqsServer Naqs.stn file contains the following information:
[ Sensor ] // predefined sensor - all fields mandatory
TypeName = TrilliumCompact // name of this prototype - may be same as model
Model = TrilliumCompact // sensor model name
SensitivityUnits = M/S // units of ground motion: M, M/S or M/S**2
Sensitivity = 0.3e9 // counts per unit of ground motion
SensitivityFreq = 1.0 // frequency at which sensitivity is correct
CalibrationUnits = VOLTS // calibration input units: VOLTS or AMPS
CalCoilResistance = 133000 // calibration coil resistance in ohms
CalCoilConstant = 100 // calibration units per m/s/s
CalEnable = 2 // digital enable signal for calibration
CalRelay = 0 // analog relay for calibration (0 = use channel number)
MassCenterEnable = -1 // digital enable signal for mass centering
MassCenterDuration = -1 // duration of mass centering signal (optional)
CalSource = Trident // gives the source of the Cal signal
Note that the CalCoilResistance and CalCoilConstant parameters need to be
adjusted according to the selected model of Trillium Compact. The computation of
the nominal system sensitivity of your model is described in Section 5.3 “Increasing
System Sensitivity” on page 32. The correct values for your model can be found in
Section 9.1 “Frequency Response for 120 s and 20 s Models” on page 45. The
CalCoilConstant in V/(m/s²) is simply the inverse of the calibration input sensitivity in
(m/s²)/V.
This section does not refer to Trident 305 digitizers. A Trident 305 is configured though the
NMXbus-enabled device to which it is attached, such as a Taurus or Cygnus. Refer to the
Trident 305 user guide and the user guide for the NMXbus device for configuration details.
Nanometrics UI Configuration Tab
Value Notes
Section Setting
Front End Input Range 40 Vpp
Sensor Control High Voltage Level +5 V
Calibration Mode Voltage (active high)
Line 1 Level Low Low is equivalent to XYZ mode
and High is equivalent to UVW
mode.
Line 2 Level Low Set to High for auto-levelling
and mass centring.
Line 3 Level Not used