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USC Config - o. Create Simple Divider using Wizard

HLP1038 - Help Article

  1. Run the 'New Module Wizard' and select 'dc Signal', 'Divider' then 'Next'.
  2. Select channel 1 as 10Vdc then 'Next'.
  3. Select channel 2 as 10Vdc then 'Next'.
  • The new module wizard added a simple equation (read CH1, read CH2, divide, save (Mem4) to the settings to module definition that you are creating.
  • When the USC wizard moved from the input components to the output components the "Auto Evaluator" option calculated the expected output range of the equation based on the minimum and maximum engineering range of the inputs used.
    In this case
    0/0=error, 0/10=0, 10/0=error, 10/10=1
    Therefore the maximum expected output range in cannot be determined.
  1. The "Evaluate Equation Outputs" screen opens due to an equation evaluation error as shown.



  2. Either use "a. Go Back and Avoid the Evaluation Error" or "b. Enter Expected Equation Output Range" to overcome this problem.

a. Go Back and Avoid the Evaluation Error

  1. Click cancel on the "Evaluate Equation Outputs" screen, an information screen will open warning that the output range for the memories has not been updated.
  2. Click 'Ok' to close the information screen The program will return to the "dc Signal Divider" wizard.
  1. Click "Back" until the "dc Signal Divider" wizard is on the Channel 2 screen.
  2. Change the 'Min Value' from 0 to 0.5 and press the copy across button to change the 'Eng. Min' to 0.5
  • This change does not affect the measured value.

  1. Click next, the wizard will now move to the output components without stopping.
  • The divider wizard created a simple equation CH1/CH2, changing the minimum value of CH2 to 0.5 prevents the divide by zero error.
    • CH1min / CH2min, 0 / 0.5 = 0
    • CH1min / CH2max, 0 /10 = 0
    • CH1max / CH2min, 10 /0.5 = 20
    • CH1max / CH2max, 10 / 10 = 1
      Therefore the maximum expected output range determined by "Auto Evaluate" is 0 to 20.

b. Enter Expected Equation Output Range

  • The wizard will stop on the "Evaluate Equation Outputs" screen if;
    • The auto evaluate option is switched on (within the equation editor) and the equation simulator cannot determine the output range.
    • The engineering range for a used memory has never been entered.
    • The trim menu has been enabled, giving the operator the opportunity to change the values of some equation constants.

  • If the equation output does not auto evaluate you must enter the output range for each memory.
  • In the divider example CH1/CH2 will produce a larger and larger as CH2 approaches zero. With this in mind I chose some numbers as follows;
    • Minimum: 0 / [any number] = 0
    • Maximum: 10 / 0 = (infinite) however I assumed that CH2 may never go below 0.5 therefore the maximum expected output range is 0 to 20 (conditional).
  1. On the "Evaluate Equation Outputs" screen enter the values that you have determined for M4 minimum and maximum.
  2. Click next, the wizard will now move to the output components.
  • The wizard checks limits and set the sensitivity of the encoder using the range YOU enter.
  • The range entered will not affect the calculation when the USC operating.

Analogue Process Control Services - The Signal Conditioning Specialist