You are here: CX23-R web interface > Test configuration > Channel setup > CAN channels

CAN channels

CAN channels use Vector CAN databases or eDAQ CAN databases to decode specific signal values from incoming CAN messages on a CX23-R, MX471B-R or MX840B-R CAN connector. Since database channels extract numeric signals from CAN messages, they can be plotted and used as source channels for computed channels and DataModes.

NOTE
Channels from eDAQ CAN database files are limited to CX23-R CAN sources only.

The MX471B-R and MX840B-R support up to 128 database channels for each CAN connector. There is no limit on the number of database channels for CX23-R CAN connectors. The CX23-R also supports active queries (SAE® J1939-21 PGN requests) on up to 75 database messages per CAN connector.

NOTE
The CX23-R also supports raw CAN Message channels.

ClosedGeneric parameters

  • Connector: A unique hardware identifier created by the system. To change the device or connector, select the channel and click Change device.
  • Name: The channel name must be unique and contain valid characters (invalid characters are single and double quotes, '\', '@', '#', '&', '<', '>').
  • Description: Enter an optional detailed description of the channel.
  • Collect: Select the Collect checkbox to write the channel data to the SIE data file during a test run.
  • Chart type: Set the default chart type for the channel. Not in edit dialog.
  • Decimals: Set the default decimal places for channel displays.
  • Sample rate: Set 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.
  • Reading: Current value of the channel. Show the readings by selecting the desired channels and clicking Live update. Not in edit dialog.
  • Data type: The format of the channel data output. Not in edit dialog.
  • Expiration time: Specify the time period in seconds that can elapse without data arriving on the CAN bus before data is considered stale and the output is set to the invalid value. The value may be any real number greater than zero.
  • Invalid value: Specify the value to be set when the expiration time has elapsed without any data. The value may be any real number.
  • Hardware interface: Value is CAN.
  • Bit rate: Set the bit rate from the drop-down list of valid values. If the CAN bit rate is changed, all channels on the same port are changed to the same bit rate value automatically.
  • Termination: Set the state of the internal termination resistor as true or false. If the termination state is changed, all channels on the same port are changed to the same state automatically.
  • Request msg: For CX23-R channels, value is a hexadecimal representation of the SAE® J1939-21 compliant PGN request. This value is read-only and computed based on the CAN message ID. Only applicable when the request rate is set (not Off).
  • Request rate: For CX23-R channels, optionally set the rate for active query requests. When set (not Off), the CX23-R transmits SAE® J1939-21 compliant PGN request messages at the specified rate. Since, request messages are only requests, they may or may not be honored by the connected CAN device. Request messages are only transmitted during a test run.

ClosedScaling 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.
  • 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.
  • Prerun zero mode: Set to Interactive only to allow channel zeroing.
  • Prerun zero offset: Automatically set after zeroing a channel.
  • Prerun zero target: Specify before zeroing a channel.
  • Range min and max: Specify the expected extreme values of the channel. May be any real number.