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button in the Measure bar.In this topic: Hide
This is the description of an instrument and how it is connected to ATS SPC. You must create an instrument in ATS SPC to match the physical instrument you will use to measure parts.
Name
This is the short name which you use in data source expressions to tell ATS SPC which instruments are used to measure which features. Try to choose a name that is short and snappy but still descriptive.
Description
This is your reminder of exactly which physical instrument this represents.
Port
The port tells ATS SPC how your instrument is connected to the computer. Choose the appropriate port from the drop down list. For more details see: Instrument Ports
Calibration
Calibration refers here not to the accuracy of the instrument but to ensuring that ATS SPC displays the same measured value as the instrument itself.
Digital electronic instruments, such as micrometers and callipers, which connect via RS232 generally, do not require calibration under ATS SPC and you can leave the calibration box unchecked. If you are using analog probes (e.g. LVDTs, half bridges etc.), or an instrument which does not transmit exactly what it displays, then check the calibration box.
Related topics: Calibration
Values
Setting
Masters
ATS SPC uses two calibration values, resolution and origin, to perform a ‘y = mx + c’ type correction to the raw instrument data.
ATS SPC multiplies the raw instrument data by the resolution value to obtain a measurement in standard units.
It then adds the origin value to the instrument data to ensure it corresponds with the instruments displayed measurement.
Resolution
Some instruments transmit measurements in non-standard internal units (e.g. micrometers in microns or tenths of a thou, or callipers in hundredths of a millimetre) and ATS SPC must convert these to millimetres or inches (or any other units) before they are used.
To convert such data to standard units ATS SPC multiplies the raw data by the ‘resolution’ value…
RawData x Resolution = Measurement
For example: a Microstat RR micrometer measures a bar diameter as 12.543mm but transmits in microns (0.001mm) as 12543 so…
12543 x 0.001 = 12.543
Origin
Some instruments have a natural reset point at a value other than zero (e.g. bore gauges) but transmit data as offsets from the zero point. To display this data correctly ATS SPC needs to know the value of the instrument’s natural reset position (its origin) so it can add this back into the data. The calculation now becomes…
Raw Data x Resolution + Origin = Measurement
For example MicroBG RR instrument has an origin at 20.093 and transmits data in microns. When it is measuring a bore of 21.195, it actually transmits 1102…
1102 x 0.001 + 20.093 = 21.195
Analog instruments, such as LVDT and half bridge probes present a more difficult calibration problem however and must be handled using Setting Masters.
Some instruments do not have known or fixed resolution values. Analog probes, for instance, depend on the conditioning circuit for their resolution and it is very difficult to predict what the resolution of a particular combination of probe and conditioner will be. In such cases ATS SPC can calibrate the instrument using two accurately known setting masters. When an instrument is placed in turn on each master, ATS SPC uses the raw data from the instrument to calculate what resolution and origin values will give the correct measurement for the two masters.
For more details see
Calibrating
an Instrument
Calibration
Values
An Instrument Port is a connection point on your computer where an instrument may be plugged in. Ports may be RS232 serial, i.e. your computer’s ‘COM’ ports. They may be provided by interface cards such as the ATS ‘Probe Card’ or ‘Instrument Card’.
Some types of port support only one instrument type, others support many. The RS232 COM ports support Callipers, Microstat micrometers, and Mettler weigh scales among others. ATS SPC handles these by pretending that each physical COM port is really several different ‘logical’ instrument ports that all use the same connector on the computer. Clearly you can have only one instrument at a time plugged into COM1 so you can’t use the COM1 Calliper port at the same time as the COM1 Microstat port.
Port Names
ATS SPC names the ports to show both the physical connection and the logical port…
Port_COM1_RS232M3010
All port names start with ‘Port’ and use the underscore character to separate the different parts of the name.
The second part indicates the physical connection to the computer, here ‘COM1’.
The third part indicates the instrument type supported, here the RS232 version of the ATS M3010 Calliper.
The ATS ‘Instrument Card’ supports both quadrature scales and Digimatic type synchronous serial instruments. Its port names look like…
Port_
C8Instrument_Quadrature_Port1
..or…
Port_C8Instrument_SyncSerial_Port3
Each Instrument Card has 4 quadrature ports and 4 Digimatic ports.
Card Addresses
The ATS interface cards each take up a small amount (16kB) of upper memory space and ATS SPC can distinguish one card from another by its memory address. If your computer has two instrument cards fitted you may have port names like…
Port_C8Instrument_Quadrature_Port1
..and…
Port_CCInstrument_Quadrature_Port1
..or…
Port_D0Instrument_Quadrature_Port1
Creating an instrument is the process of telling ATS SPC about a measuring instrument you want to connect – what it is called, how it is connected to the computer, what measuring units it uses etc. For details about the information ATS SPC needs see: Instrument Properties
1. Choose Edit from the Instruments menu.
2. In the Instruments dialog press the New button.
3. In the Instrument Definition dialog enter the following instrument details…
· Name – short and snappy for use in data source expressions
· Description – to remind you which instrument this is.
· Port – from the drop down list, choose where the instrument is connected to your PC.
· For most instruments that’s all you need do but for some you may have to enter calibration or setting master details.
For more details see: Instrument Properties
4. Press the OK button to save your instrument definition.
5. You can test the new instrument by checking it in the instrument list and then pressing the Test button. See Testing an Instrument for details.
After you have created a measuring instrument you can change its details any time you need to. The Edit Instrument functions give you access to exactly the same range of properties you saw when you first created the instrument.
1. Choose Edit from the Instruments menu.
2. In the Instruments dialog click on the name of the instrument you want to edit.
3. In the Instrument Definition dialog you can change any of the instrument’s properties.
For more details see: Instrument Properties
4. When you have finished, press the OK button to save your changes, or Cancel to abandon them.
Deleting an instrument is permanent and cannot be undone – except by re-creating it from scratch.
Deleting an instrument that is currently in use by a batch will render that batch inoperative. You can use it again by editing the feature data sources to use a different instrument, or by recreating the instrument. If you do the latter you must re-open the batch before it will recognise the new instrument.
1. Choose Edit from the Instrument Menu.
2. In the Instruments dialog check the box next to the instrument you want to delete. You can check several if you want to delete more than one instrument.
3. Press the Delete button.
4. Back in the Instruments dialog press the Done button.
ATS SPC provides the Test function so you can examine the data received from a measuring instrument before it is changed by any data source expression. This is a useful way to separate instrument problems from expression problems.
If the instrument has data entry or reset buttons that ATS SPC recognises then the Test functions shows the state of the buttons as well.
Some instruments support remote control, particularly remote resetting and these can be reset from the Test dialog. Note however that, if the instrument does not support remote resetting, this may result in the ATS SPC display showing zero while the instrument itself shows another value.
1. Choose Edit from the Instrument Menu.
2. Check the box to the left of the instrument you want to test. You can check several boxes and test a number of instruments at once if you wish.
3. Press the Test button.
4. The Test dialog shows the raw data received from each selected instrument, the state of its buttons, if any, and the instrument status – whether it is present and sending good data, out of range, not responding etc.
5. If the instrument supports remote control you can reset or zero it by pressing the Reset button.
This is the process of returning the instrument’ reading to zero, or in some cases to some pre-set starting value. If the instrument supports remote resetting then ATS SPC will be able to reset it when you choose the Instrument Reset function from any of the menus or toolbars. If it doesn’t then you must reset the instrument manually.
When you reset an instrument ATS SPC checks to see if its position is close to that in which it was last reset. If not you will see a warning message telling you that the instrument may not be correctly positioned at its origin point. It is possible that you hit the reset button accidentally or you are using the wrong reset master for the instrument. You may also see this warning message the very first time you try to reset an instrument.
You can reset instruments directly from an open batch, or from the Instruments dialog. In the former case ATS SPC automatically selects all the instruments in the current measuring set and resets them. In the latter case you must choose which instruments to reset.
To reset the instruments in the current set of your current batch Choose
Reset from the Instruments menu, press the shortcut key, F2, or press
the Instruments Reset ()
button in the Measure bar.
To reset any arbitrary instrument…
1. Choose Edit from the Instruments Menu.
2. Click on the name of the instrument you want to reset.
3. Press the Test button
4. In the Instrument test dialog press the Reset button.
5. If you see a warning message, confirm that the instrument is correctly positioned for resetting (e.g. on the correct reset master) and click OK or press RETURN. (If the instrument is not correctly positioned for resetting click Cancel or press ESCAPE and start again.)
6. Press OK to close the Test dialog and then OK again to close the Instruments dialog.
Calibration, here, means the art of making the ATS SPC display read the same as the instrument. It has nothing to do with the accuracy of the instrument itself.
Calibration is particularly useful for instruments which do not have a known, fixed resolution, such as LVDT probes and other analog instruments. By measuring two accurately known ‘setting masters’ ATS SPC can calculate the resolution and origin values to convert the raw instrument data to the required measuring units. ATS SPC can therefore make use of any linear measuring instrument, regardless of its internal scale units.
When you calibrate an instrument ATS SPC checks to see that its new resolution is close to the previous value. If not you will see a warning message telling you that the instrument may not have been correctly positioned on one of the calibration masters. It is possible that you hit the Accept button accidentally or you are using the wrong master for the instrument. You may also see this warning message the very first time you try to calibrate an instrument. How close the new resolution must be to the old is determined by the calibration tolerance in the Instruments page of the Options dialog. See Instrument Options on page 117 for details.
You can calibrate an instrument directly from an open batch, or from the Instruments dialog. In the former case ATS SPC automatically selects all the instruments in the current measuring set. In the latter case you must choose which instruments to calibrate.
To calibrate the instruments in your current batch go to step 4.
1. Choose Edit from the Instruments menu.
2. Select one or more instruments to calibrate by checking the box to the left of the instrument name(s).
3. Press the Calibrate button (now go to step 5).
4. Choose Calibrate from the Instruments menu.
5. The Calibrate dialog shows the selected instruments, their current raw data, and the value of the first setting master for each.
Place the instrument on the first master, or, if calibrating a fixture, place the first master in the fixture, and ensure it is correctly seated.
6. Click the Accept button, or press RETURN.
ATS SPC then shows the value of the second master for each instrument.
7. Measure the second master in the same way as the first. And, when ready, click Accept or press RETURN again.
If you see a warning message that one or more instruments did not move you should click OK and try again. Possibly you hit the Accept button accidentally before using the second master.
If you see a warning message about the resolution of an instrument changing this means that the calibration has resulted in the resolution changing more than it might be expected to. Possibly you have tried to calibrate using the wrong masters. This message can also appear the very first time you try to calibrate an instrument. See Instrument Options on page 131 for more details.
If all is well, ATS SPC shows the calibrated value from each instrument and you can check accuracy at other positions if you wish.
8. You can repeat either setting master, or both, if necessary until you are satisfied with the calibration. Press OK when you have finished.