Measurement-computing Data Acquisition Systems rev.10.4 Bedienungsanleitung PDF herunterladen (Seite 168)

Parameter Type Definitions

RtdType-(RtdType)

Definition Description

Dbk9RtdType100

Value for a 100 ohm RTD

Dbk9RtdType500

Value for a 500 ohm RTD

Dbk9RtdType1K

Value for a 1000 ohm RTD

Avg

Definition Description

avg = 0

Specifies block averaging--all scans are averaged together to compute a single value for each channel

avg = 1

Specifies no averaging--each scan’s readings are converted into measured signals

avg ≥ 2

Specifies moving average--each scan’s readings are averaged with the avg-1 preceding scans’

readings before conversion.

Returns

DerrRtdParam Setup parameter out-of-range

DerrRtdTArraySize Temperature storage array not large enough

DerrRtdValue Invalid RTD type

DerrNoError No error

For more details on error messages refer to the Daq Error Table.

Function Usage

For all functions of the form daqCvt..., raw data to be converted must be unsigned

(i.e., the dafUnsigned value must be set using the daqAdcSetScan function).

For T/C and RTD conversion, users of Daq/2000 Series devices* and/or Daq PC Cards must

be sure that the main unit is using ten volt range gains settings, either unipolar (0 V to 10 V)

or bipolar (-5 V to +5 V).

See the “T/C Gains Settings” section in the daqCvtTCConvert function entry for the

appropriate settings.

* Daq/2000 Series devices include DaqBook/2000 Series, DaqScan/2000 Series, DaqLab/2000

Series, and DaqBoard/2000 Series devices.

The daqCvtRtdSetupConvert combines the operations of the both the daqCvtRtdConvert function

and the daqCvtRtdSetup function. For more detailed information on using RTDs refer to the entry for the

daqCvtRtdConvert function.

Moving Averages

To better illustrate the moving average feature of the avg parameter, suppose the avg value is set to 3. Since

each scan’s readings are averaged with the preceding scan, the results from the first scan (which has no

preceding scan) are not averaged at all. However, the results from the second scan are averaged with the first

scan, and the results from the third scan are averaged with the preceding two scans. After the third scan, each

subsequent scan is averaged with the preceding two scans (since the avg value is 3, and avg-1 is two). In

another instance, if the avg value is set to 5, then each scan after the fifth scan would be averaged with the

four preceding it.

4.3-42 Daq API Command Reference 908494 Programmer’s Manual

1 2 ... 163 164 165 166 167 168 169 170 171 172 173 ... 365 366

Kommentare zu diesen Handbüchern

Keine Kommentare

Measurement-computing Data Acquisition Systems rev.10.4 Bedienungsanleitung Seite 168

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Hardware Measurement-computing Data Acquisition Systems rev.10.4