To Access an Instrument’s Properties:
Right-click the instrument in the tree or graphical view and choose Properties from the context menu
Double-click the instrument in the tree.
The properties for an instrument will vary depending on the class of instrument (laser tracker vs. arm vs. scanner, etc.), but the basic controls and layout is much the same. Shown below are two examples (a Leica AT960 Laser Tracker and a Hexagon Absolute arm). The Instrument index in the SA Treebar as well as the model and port are listed at the top of the dialog.
The sensor control section allows you to adjust the graphic model of the instrument. For spherical devices, you can adjust the vertical, horizontal, and distance degrees of freedom. For an arm, you can adjust the rotation value for each link. Other instrument types (such as laser scanners) may not have any adjustment at all. After selecting the degree of freedom and associated value, click the Apply button to see the changes. Or, click the up/down arrows to increment the rotation value.
It may be desirable to apply a scale to an instrument’s measurements to account for thermal expansion and contraction of a measured part. For example, suppose you have a nominal model that has been designed for 68°F (20°C) conditions. If you are laying off nominal features from that model on a hot day--say 95°F (35°C)--then you will want to scale the instrument’s measurements down from 95°F to 68°F so that the instrument and the nominal model are adjusted to the same temperature reference. One way to achieve this is to scale the instrument’s measurements.
When an instrument scale factor is applied, all measurements from the instrument will be scaled appropriately relative to the instruments origin. For example, an instrument observation that is normally at a radius of 100” from the instrument will be 101” from the instrument at a scale factor of 1.01. Instruments that are currently using a scale factor other than 1.0 will appear with a special yellow icon in the tree and will be listed as a scaled instrument.
All instruments have error in their measurements, and as a result every measurement from an instrument has some uncertainty. Each class of instrument (laser tracker, PCMM arm, total station, etc.) has different set of uncertainty characteristics. For example, laser trackers have uncertainties for the horizontal and vertical encoders, as well as an uncertainty for the distance measurement. PCMM arms, on the other hand, have an angular uncertainty for each link of the arm. Additionally, each instrument within a specific instrument class has different values for the uncertainties. The uncertainty values for a newly calibrated laser tracker in pristine condition from a manufacturer will be different from those of an old, dirty, poorly calibrated tracker from the same manufacturer.
Instrument Graphics (PCMM arms only)
PCMM arms have an Instrument Graphics button that appears directly under the Edit Uncertainty Variables button. This button calls up the Instrument Graphics dialog
Restore Default Graphical Model. The kinematics for a PCMM arm are refined as points are measured. These kinematics only affect how the arm is depicted in the graphical view--not the accuracy of the measurement data itself. Clicking this button will restore the default graphical model that has been stored with the instrument definition
A numerical monitor and graphical indicator can be enabled to display the current status of an instrument orientation to gravity within a job file. More details can be found under Station Controls > Instrument Straighten.
SA offers the ability to manually calibrate an arm graphical model based on measurements recorded in the job file. Once calibrated this new calibration is saved in C:\Analyzer Data\Persistence. If a calibration is found for you arm SA will load it automatically when it connects.
Solve for Graphical Model Using All Measurements in Job. This option will consider the measurements that the arm has observed, and recalculate the kinematics for the arm.
This value determines (in seconds) how long an instrument interface will attempt to connect to the instrument until it times out with an error, stating that the instrument cannot be found. Enter zero to continue checking indefinitely.
Several instrument communication controls have been added to allow users to tailor performance based upon their computer performance and instrument requirements. These include:
Instrument Interface Response Timeout. This value is used to define how long SA waits for a response from an instrument in seconds. If no response is received after the specified duration a break in communication will be assumed to have occurred such as might be caused by a firewall turning on or a cable getting unplugged. Aso, some data transmitted to an instrument may be such that the function sending it will wait for a response before exiting the function. This value establishes the amount of time the function will wait before it exits on a “timeout” condition.
Packet Warning Threshold. Measurements from an instrument are stored in packets and processed by SA as fast as possible. However, when recording large amounts of data at a fast rate a backlog can occur and a user notification can be useful. This warning threshold defines a minimum threshold below which no warning dialogs will be shown. This a dynamic threshold which determines, based upon the number of packets processed and the time required to process them, how many packets could be expected to be processed over an interval of 5 seconds.
Packet Bundle Interval. This interval is used to control the minimum update rate of the graphics and user interface while measuring. The instrument socket thread will present data for the incoming “PendingPacket” buffer as fast as the instrument will send them. The data is only processed upon receiving a notification from the instrument socket thread that there is data available. The time interval between these notifications will not be less that this time interval.
Filter Instrument Update Packets. This check box controls whether graphical updates from an instrument are stored and processed or filtered out and ignored to accelerate data processing speeds. If the filter is asserted, only the last instance of an update packet will be processed even if there are several packets of this sort in the packet bundle being processed.
Notes Field.
Transform. The Transform button is used to transform (move and rotate) the instrument. More information about transformation can be found in the Move section.
Covariance.