Measurement Computing DAQFlex - Manual (Page 11)

11
Chapter 5
Calibrating a device
The message-based firmware provides messages that let you calibrate the analog inputs or outputs on a
device.
Calibrating analog inputs
To modify the analog input calibration settings, complete the following steps:
1.
Send the "AICAL:UNLOCK" message to unlock the AICAL component and put the device into
Calibrate Mode.
When the AICAL component is unlocked, sending a message to any component other than AICAL
will lock the AICAL component.
2.
Send the "AICAL:REF=value" message to set the calibration voltage.
Refer to the device-specific information to determine the calibration voltages supported by the
device.
The calibration voltage value is stored in EEPROM and can be retrieved with the "?AICAL:REFVAL"
query.
3.
Send the "AICAL{ch}:RANGE=value" message to set the channel and range value to calibrate.
4.
Send the "AICAL{ch}:SLOPE=value" message to set the slope for the current range setting.
5.
Send the "AICAL{ch}:OFFSET=value" message to set the offset for the current range setting.
6.
Send the message "AICAL:LOCK" to lock the AICAl component and exit Calibration Mode.
The device returns INVALID if any AICAL property message is sent while the AICAL component is
locked.
Note: The channel {ch} message variable is ignored on devices with channels that are not individually
configurable.
Refer to the Analog input calibration messages on page 12 for details about the AI calibration messages .
Calibrating analog outputs
To modify the analog output calibration settings, complete the following steps:
1.
Send the "AOCAL:UNLOCK" message to lock the AOCAL component and put the device into
Calibrate Mode.
When the AOCAL component is unlocked, sending a message to any component other than AOCAL
will lock the AOCAL component.
2.
Send the "AOCAL{ch}:SLOPE=value" message to set the slope for the current range setting.
3.
Send the "AOCAL{ch}:OFFSET=value" message to set the offset for the current range setting.
4.
Send the "AOCAL{ch}:VALUE=value" message to set the value of the AO channel being calibrated.
5.
Send the message "AOCAL:LOCK" to lock the AOCAl component and exit Calibration Mode.
6.
The device returns INVALID if any AOCAL property message is sent while the AOCAL component is
locked.
Note: The channel {ch} message variable is ignored on devices with channels that are not individually
configurable.
Refer to the Analog output calibration messages on page 16 for details about the AO calibration messages.