Configuring a Digital or Relay Output Channel

A Digital or Relay Output Channel generates a digital output based on the configuration.

To configure a Digital or Relay Output Channel:

1. From the EPM Data User Interface screen, select Options - Device I/O - Hardwired I/O:

   

2. The Hardwired I/O screen displays, select the required Relay Output module from the left-hand side pane and the associated channels display in the right-hand side in the Channels tab:

   

3. Select the required Digital Output Channel and the properties display in the right-hand side:

   

4. If you are not already in Configuration lock, the Configuration lock screen displays:

   

   Enter a reason if required and then select Confirm . The system configuration is now locked pending the submission of your update and the Configuration Locked icon displays on the status bar.

   Note - Configuration lock does not affect the operation of the EPM device.
   See Configuration Lock for details.

5. Complete as required:

   • Digital Output Channel - Select Expand if it does not expand automatically:

     • Hardware:

       

       • Cluster - Cluster where the module is plugged in, such as Local I/O.

       • Slot Number - Slot number (1…n) where the module is plugged in.

       • Channel Number - Channel number (1…n) in the module.

     • Main:

       

       • Type - Select the configuration type of the channel:

         • Off - Channel is disabled.

         • DO - Channel is enabled.

       • Sense - Select how the input demand is interpreted in relation to the physical Digital Output (DO) behavior:

         • Direct:

           • When the Demand is False, relay contact opens, or logic output drives electrically low.

           • When the Demand is True, relay contact closes, or logic output drives electrically high.

         • Inverted:

           • When the Demand is False, relay contact closes, or logic output drives electrically high.

           • When the Demand is True, relay contact opens, or logic output drives electrically low.

       • Fallback Action - Select the behavior of the physical output when the demand status is bad or when the I/O module is not being updated by the application, for example, when there is a communication issue:

         • Drive Low - The relay contact opens, or logic output is electrically low.

         • Drive High - The relay contact closes, or logic output is electrically high.

         • Hold - The output remains the last demand value with a good status until the status is good again.

       For example, If the input demand = True and Sense = Direct, then the DO closes its relay contact / drives high. If Sense = Inverted, the same True demand would open the relay / drive low.

6. From the Chart and presentation settings, select Expand if it does not expand automatically, and then complete the following:
   

   • General Settings:

     

     • Closed String - Enter the text string for the digital output closed state.

     • Open String - Enter the text string for the digital output open state.

     • Color - Select a color from one of the 56 available colors:

       

   • Scale & Zone Settings:

     

     To set the chart scale and zoning for this channel:

     • Scale Enable - Tick to enable scale configuration and specify the scale type and the number of divisions required:

       • Scale Type ( available only when Scale Enable is enabled) - Select one of the following options:

         • Logarithmic - Divisions are displayed using a logarithmic scale. This option is suitable for analyzing data spanning multiple orders of magnitude.

         • Linear - Divisions are displayed at equal intervals. This option is ideal for displaying uniformly distributed data:

           • Scale Division Major ( available only when Scale Type is Linear) - Enter a value, or use the Plus or Minus to set the major divisions to be included on the chart (valid range 1 to 20).

           • Scale Division Minor (available only when Scale Type is Linear) - Enter a value, or use the Plus or Minus to set the minor divisions to be included on the chart (valid range 1 to 20).

             Note - Scale divisions have no impact on a chart grid, they are only for scale. The grid on the chart is defined by the division settings on the group, see Configuring Groups Settings for details.

     • Scale maximum (Unit) - Enter a value, or use the Plus or Minus to set the upper limit of the scale's range.

     • Scale minimum (Unit) - Enter a value, or use the Plus or Minus to set the lower limit of the scale's range.

     • Zone maximum (%) - Enter a value, or use the Plus or Minus to set the percentage offset for the upper limit of the scale and trendline relative to the top of the chart (valid range 5 to 100).

     • Zone minimum (%) - Enter a value, or use the Plus or Minus to set the percentage offset for the lower limit of the scale and trendline relative to the bottom of the chart (valid range 0 to 95).

       Note - The minimum value must be less than the maximum value by 5 or more.
       Tip - The Zone settings offset a scale and its associated trendline relative to the chart grid. This is useful when displaying multiple trends with similar value ranges, which would otherwise overlap and become difficult to distinguish. For example, several digital trends switching between 0 and 1 can overlap, making them difficult to distinguish unless each is defined a different Zone.

7. From Alarms, select Expand if it does not expand automatically, and then select Add alarm to configure an alarm on this channel. See Configuring an Alarm for details.

8. Once complete, select Review pending changes screen to review updates to the configuration, and submit them. See Reviewing and Submitting Changes for details if required.

   Note - Reviewing and submitting can be completed in bulk once you have completed all your additions and/or updates.