Digital I/O Setup

For an overview of __prod_name Digital I/O as well as definitions of Digital I/O specific terms, see the Digital I/O Overview page .

These settings are used to control how the Digital I/O ports are setup and how __prod_name DAS  process the TTL values before passing the data to the acquisition entities or outputting the values to the TTL output port.  The Digital I/O setup is shown via the View menu in __prod_name.  All changes made in this dialog are applied immediately.



Digital I/O Setup Dialog

1.  Input Port List	A list of all of the ports that are currently set for TTL input.  Clicking on one of the items in this list will allow you to adjust parameters of the port as well as see more details.
2.  Board Description	The description shown consists of three parts: the device name, the port number and the detailed port description.  The device name and port number will be used to identify this particular item when using Digital I/O commands . Example: The highlighted item in the input port list above has a device name of AcqSystem1_0, the port represented by this item is port 2, and the detailed description informs us that this device is the I/O port on the __lynxsx_hardware_name labeled Ports 2/3.
3.  Scan Rate	Also known as the sampling frequency, this is the rate at which values will be written to or read from the selected port.  The sampling frequency for all Digital I/O devices that are part of an acquisition system is set by the acquisition system and cannot be changed independently.  Add-on Digital I/O devices may have their sampling rate changed depending on the capabilities of the hardware.  See the Digital I/O Overview section for more information.
4.  Total Bits	The total number of bits available for this port.
5.  Event Record Generation	If this box is checked, event records will be generated whenever a change is made to the value of the port.* *See the Strobe Selection item for exceptions to this rule.
6.  Strobe Selection	Digital I/O ports that are set to input have the option of selectively capturing the value currently on that port by strobing (a low to high TTL transition) the most significant bit (MSB) of the port (i.e. bit 7 of an 8 bit port).  If this option is checked, whenever __prod_name detects a low to high transition on the MSB, the entire value of the input port will be read and an event record generated (if enabled, see the Event Record Generation item on this page).  Any bit changes that occur between strobes of the MSB will not generate event records.  If you desire to have an event record generated for every bit change on the input port, disable (uncheck) this option. NOTE: The MSB will always be part of the TTL value.  This means that the MSB will always be set to 1 when the TTL value is saved to the event record. For more detailed information as well as examples, see the -SetDigitalIOUseStrobeBit command.  The checked state indicates a TRUE value for the -SetDigitalIOUseStrobeBit command and the unchecked state is a value of FALSE.
7.  Device Selection	The selected device from the Output/Input list. Changes made to the Bits per Port apply to this device.
8. Bits per Port	Changes the number of bits used in each port of the selected device. Options in the dropdown correspond to the available configurations of the hardware selected. NOTE: Changing this selection will reset all Digital IO settings.
9.  Output Port List	A list of all the ports that are currently set for TTL output.  Clicking on one of the items in this list will allow you to adjust parameters of the port as well as see more details.
10. Make Output	Changes the direction of the item selected in the Input Ports list from input to output.  If the item cannot be changed, a message will be shown explaining why the change could not take place at that time.
11.  Make Input	Changes the direction of the item selected in the Output Ports list from output to input.  If the item cannot be changed, a message will be shown explaining why the change could not take place at that time.
12.  Pulse Duration	The amount of time that a pulsed bit will remain in the pulsed direction when a TTL pulse is generated on one of the bits in this port.  See the -SetDigitalIOPulseDuration and -DigitalIOTtlPulse commands for more detailed information as well as examples.
13.  Close	Closes this window.