Setting and Reading the Power-Up States of Digital Output Lines

The following devices support programmable power up states:

• 6509
• 651x (6512, 6513, 6514, 6515)
• 652x (6525, 6527, 6528),
• All M Series boards (62xx)
• All X Series boards (63xx)

You can set power-up states in NI Measurement & Automation Explorer (NI MAX) or with the DAQmx Set Power Up States  (Digital) function/VI. Using NI MAX is the recommended method. The programmable states are :

• Logic low (0 V-0.8 V)
• Logic high (2 V-5 V)
• Tri-state (floating)

Note: You can only specify a programmable power-up state of tri-state on devices with a configurable direction.

Note: I/O direction on static DIO devices is port-configurable only. Therefore, you can set the power-up state to tri-state only on a port-by-port basis. You can, however, set individual digital output lines in a port to logic low or logic high.

Updating these sets the states to which to set physical channels on a device when the DAQ device powers up or when you reset the device. A device stores power up states in non-volatile memory that you can write to only a limited number of times. The write only occurs if a setting you request is different from the one currently stored. This article details the steps to alter these states in NI MAX and LabVIEW as well as how to read the states from the EEPROM in LabVIEW.

 

Setting power-up states in NI MAX (recommended method):

1. Open NI MAX.
2. Expand Devices and Interfaces » NI-DAQmx Devices.
3. Right-click on your device and select Configure.
4. Select the Power-up States tab.
5. Select the port under the Port Name drop-down menu and the appropriate state for each line of the port.
6. Click OK to write the settings to the device.
7. Right-click on your device again and select Reset for the settings to take effect.

 

Setting power-up states in LabVIEW:

1. Open LabVIEW.
2. Under Measurement IO » DAQmx » DAQmx Advanced » System Setup, place the NI-DAQmx Set Power-Up States VI on the block diagram.
3. Right-click and create » control for both the device in and power up states terminals.
4. Under Measurement IO » DAQmx » Dev Config, place the DAQmx Reset Device VI.
5. Switch to the front panel and select the appropriate settings for device in and power up states.
6. Run the program to write the settings to the device.

 

Reading power-up states from EEPROM in LabVIEW:

1. Open LabVIEW and create a new VI.
2. Under Measurement IO » DAQmx » DAQmx Advanced » System Setup, place the NI-DAQmx Get Power-Up States Polymorphic VI on the block diagram. Configure it for Digital » State.
3. Right-click and create » control for the device in. Pass the DAQmx device handle to control.
4. Right-click and create » indicator for power up states terminal.
5. Run the program to read the settings from the device.

Updates the states to which to set physical channels on a device when the device powers up or when you reset the device. To determine the response time of the power-up states, please consult the specifications of each individual card.