Digital input channels (pulse counters)
Digital input pulse counter channels with programmable thresholds are sourced from EDIO layers connected to the EXRCPU or from ELDIO layers connected to the EXRLCPU. See EDIO/ELDIO digital input/output layers for more information.
NOTE
The term pulse counter is used as a generic term to refer to channels that measure parameters that are derived from analog signals and are subsequently processed as “pulse events”.
Generic parameters
- Connection: A unique hardware identifier created by the system.
- Reading: Current value of the channel. Show the readings by selecting the desired channels and clicking
Live update. Not in edit dialog.
- Units: For most channel types, the user can enter the physical units as desired; however, for some channel types (i.e., most temperature channels, and any bridge channel that uses the Strain gage scaling mode), the user can only select an option provided in the drop down list box.
- Name: The channel name must be unique and contain valid characters (invalid characters are single and double quotes, '\', '@', '#', '&', '<' and '>'). Invalid channel names are 'true' and 'false' (case sensitive).
- Description: Enter an optional detailed description of the channel.
- Sample rate: Select the desired channel sample rate. If the sample rate changes, all dependent computed channels and DataModes™ are changed automatically.
- Measurand: Enter an optional measurement type.
- Input mode: Select the digital input mode from the options presented. In the channel edit dialog, a wiring diagram for the selected input mode is available for reference.
- Data type: The format of the channel data output (read only).
- Collect: Select the Collect checkbox to write the channel data to the SIE data file during a test run.
- Decimals: Select the default decimal places for channel displays. Use the “Auto” option to apply the settings defined in the User Preferences. See User preferences > General > Decimal point handling for more information.
- Network node: A CPU serial number shows for a module or camera channel's network node.
- Custom column information: For each column to be used, enter a unique name for the column header. Select either the “Text” or the “Numeric” sorting option.
EDIO/ELDIO specific parameters:
- Threshold mode: Only the Static mode is available.
- Low threshold and High threshold (mV): The threshold limits determine when an input channel switches from a logic value of 1 (Boolean True) to a logic value of 0 (Boolean False) and vice-versa. The High threshold is where the switch to logical 1 occurs, and the Low threshold is where the switch to logical 0 occurs. The difference between the High and Low thresholds is fixed by the hardware at (nominal) 1000 mV. For the High threshold, the maximum is 4800 mV and the minimum is 1 mV. Threshold values must be the same for all Digital input and Digital pulse counter channels on any given DIO Bank.
- Transducer power: Set the transducer power mode to Off, 5 V or 12 V. If the transducer power is changed, all digital input and output channels sourced from the same Bank are changed to the same mode automatically.
- Input mode: The following modes are available.
- Pulse frequency: The pulse frequency in S/s (computed as the reciprocal of the “pulse period”).
- Pulse period: The time period in seconds between falling edges.
- Pulse high period: The time period in seconds that the signal is high (i.e., the time period between a rising edge and a falling edge).
- Pulse rate: The number of pulses found in each sample period (based on falling edges).
- Encoder: The encoder position using quadrature counting.
- Pins: The specific connector pin(s) that the input signal(s) is connected to. All input modes except the Encoder mode use only one input pin (e.g., any of pins 1-4 on each of the 9 EDIO connectors or 3 ELDIO connectors). The Encoder mode uses 2 pins (e.g., pins “1-2”, “3-4”, etc.).
Scaling parameters
-
Scaling mode: Set the channel scaling mode.
- Defined slope intercept: Specify the Slope and Intercept of the scaling line.
- Defined zero span: Specify the Electrical zero of the sensor scaling line. Enter both the Electrical span and the Physical span.
- Defined two point: Specify the Electrical 1, Physical 1, Electrical 2 and Physical 2 points to define the scaling line.
- Experimental two point: Use the Experimental two point scaling option to define the two point parameters based on experimental measurements.
- Electrical units: Electrical units of channel input. The defined sensor scaling is used to convert data from Electrical units to Physical units.
- Calibration date: When using the channel calibration dates and locks option, the UTC calibration date (yyyy-mm-ddThh:mm:ss) is shown when the channel is calibrated. See Calibration options for more information.
- Units: Physical units of measurement for the channel.
- Electrical 1: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
- Physical 1: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
- Electrical 2: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
- Physical 2: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
- Electrical zero: Specify for Defined zero span scaling mode.
- Electrical span: Specify for Defined zero span scaling mode.
- Physical span: Specify for Defined zero span scaling mode.
- Slope: Specify for Defined slope intercept scaling mode.
- Intercept: Specify for Defined slope intercept scaling mode.
- Range min and max: Specify the expected extreme values of the channel. These parameters are most significant for the EBRG and EHLS layer channels because they are used to set the signal conditioner gains and offset. For other channel types, they are less significant. However, for all channel types, they are used as defaults for the histogram bounds in applicable data modes, and they can also be used as default y-axis limits for strip chart displays.
- Warning and Alarm min and max: Specify the desired values for warning and alarm thresholds.
- Enter a real number that defines the level in physical units, or a real number followed by the ‘%’ character that defines the level as a percent of Range max or min, or leave the cell blank to inhibit the warning or alarm.
- The percent value must be in the range of 0% to 120%.
- The % of Range max is independent of Range min and vice-versa. For example, if Range max is set to 1000 and Range min is set to -500 and 90% is used for both alarm levels, the alarms trip when the data value becomes > 900 or <-450. If the user changes the Range min to -600, the Min alarm threshold changes to -540. However, the Max alarm threshold does not change (i.e., it is still 900).
- The values of the warnings and alarms, in terms of real numbers, must satisfy the following condition for all defined parameters:
Min alarm threshold < Min warning threshold < Max warning threshold < Max alarm threshold. - A min or max warning will show a yellow background for the numbers.
- A min or max alarm will show a red background for the numbers.
Zero parameters
- Zero mode: Select one of the following options.
- Not applicable: Zeroing is not allowed.
- Interactive only: Interactive zeroing is allowed.
- Normal Test Starts: Zeroing is done automatically on every normal test start. Interactive zeroing is allowed.
NOTE
Normal test start is defined as a test started using the web browser user interface, or a test started using the remote control switch when the Remote control run mode is in use. For tests that use the Cyclic test run mode, only the test started in the user interface is applicable; test cycles started automatically after the previous test cycle are not applicable. Tests restarted on power cycles or error resets are not applicable.
- Zero target: Specify the physical value desired for the zero task. Typically, this is 0.0, but not always. For example, this parameter may be set to 1.0 (g) for an accelerometer that senses the force of gravity. In this example, the zero task would result in the channel data being offset so that the current reading is 1.0.
- Zero offset: Automatically set after zeroing a channel. The user can edit this, but that is not generally advised.