Digital I/O
Click any of the following items to learn more about the types of digital input and output channels.
Digital Input Channel—Read from Port
To configure a digital input virtual channel by port (in the Create New Channel wizard or the Digital I/O Properties window), follow these steps:
Enter the channel name and description. Click Next.
Select Read from Port from the digital type selection box. Click Next.
Select a device from the device selection box, which lists all devices containing ports for digital I/O. The DAQ device determines the number of lines per port.
Select the device port in the port selection box. You can then read all bits or lines in the port from the digital channel. Click Next.
MAX displays the port width as the number of elements in the Signal Inversion section. To apply inversion to each line in your port, check the corresponding checkbox. With this type of digital scaling, you monitor digital lines that use inverted or negative logic (state is TRUE or ON when the line is low) as positive logic. When the port is read, the value is returned to you with the selected lines inverted.
Click Finish when you are done.
Digital Input Channel—Read from Line
To configure a digital input virtual channel by line (in the Create New Channel wizard or the Digital I/O Properties window), follow these steps:
Enter the channel name and description. Click Next.
Select Read from Line from the digital type selection box. Click Next.
Select a device from the device selection box, which lists all devices containing ports for digital I/O.
Select the device port in the Port selection box. Then select one of the lines in that port in the Line selection box. If other lines have been configured as digital output channels on that port but the selected port does not support line-wise directional control, MAX marks your digital virtual channel as invalid until all lines for that port have the same direction.
Select No (do not invert) or Yes (invert) as the Signal Inversion setting for the digital line. With this type of digital scaling, you monitor digital lines that use inverted or negative logic (state is TRUE or ON when the line is low) as positive logic.
Click Finish when you are done.
Digital Output Channel—Write to Port
To configure a digital output virtual channel by port (in the Create New Channel wizard or the Digital I/O Properties window), follow these steps:
Enter the channel name and description. Click Next.
Select Write to Port from the digital type selection box. Click Next.
Select the device from the device selection box, which lists all devices containing ports for digital I/O. The DAQ device determines the number of lines per port.
Select the device port in the Port selection box. You then can write all bits or lines in the port together from the digital channel. MAX displays the port width as the number of elements in Signal Inversion section. Click Next.
To apply inversion to each line in your port, check the corresponding checkbox. With this type of digital scaling, you output digital lines that use inverted or negative logic (state is TRUE or ON when the line is low) as positive logic.
Click Finish when you are done.
Digital Output Channel—Write to Line
To configure a digital output virtual channel by line (in the Create New Channel wizard or the Digital I/O Properties window), follow these steps:
Enter the channel name and description. Click Next.
Select Write to Line from the digital type selection box. Click Next.
Select a device from the device selection box, which lists all devices containing ports for digital I/O.
Select the device port in the Port selection box. Then select one of the lines in that port in the Line selection box. If other lines have been configured as digital input channels on that port but the selected port does not support line-wise directional control, MAX designates your digital virtual channel as invalid until all lines for that port have the same direction. Click Next.
Select No (do not invert) or Yes (invert) as the Signal Inversion setting for the digital line. With this type of digital scaling, you output digital lines that use inverted or negative logic (state is TRUE or ON when the line is low) as positive logic.
Click Finish when you are done.