5 Replies Latest reply on May 2, 2018 9:22 AM by Chris Boucher

    Point Status 'L' Code

    Chris Boucher

      I have a 4-20mA analog input point that monitors the MW output of a transducer for a generator bus.  The Transducer supports a 4-20mA output.  Issue arises when the unit is not online and a small amount of station load exists which puts the input out of range of the instrument rating.  With an EGU scale of 0-28, the value may be -0.30.  Enough to set the 'L', low instrumentation rating flag.  This is causing an issue for ISO's system as the value is now labeled as a bad value.

       

      I have tried a few things with little luck.  Looking for suggestions on how to clear the L flag or other work arounds.  Thanks in advance!

        • Re: Point Status 'L' Code
          Abe Chandrabose

          Hi Chris,

           

          The Calculation Processor application has Min and Max functions included since the G3_P4 release, and this can help create a zero percent cutoff for an analog point.

          Using the 4-20mA Hardware Analog that is scaled as 0 (EGU Min) to 28 (EGU Max), create one Calculation with the Result Type of Analog, with two Inputs, and set the EGU Min to 0 and EGU Max to 28.  Create one Constant with a value of 0.0 (include the one decimal place so the result doesn't truncate the decimal value).  When you configure the Calculation, set Input #1 to Type ANA, the Function to MAX, and Input # 2 to CON.  Click on the Map Analogs button and map in the 4-20mA Hardware Analog that is monitoring the MW output of the gen bus.  After submitting the change, click the Map Const button and map in the Constant of 0.0 that was created.  So the result of the Calculation will send a constant of 0.000 when the 4-20mA Hardware Analog is below 0.000, and will switch to the Hardware Analog when it is at 0.001 or above.  The result of the Calculation would be mapped to the Port or Socket used by the ISO.

           

          Let us know if this solution will work for you.

           

          Thank you,

          Abe

            • Re: Point Status 'L' Code
              Chris Boucher

              Abe,

               

              This works perfectly!  Thank you very much!

              • Re: Point Status 'L' Code
                Chris Boucher

                Abe, the latest firmware I can get for our SAGE 2300 is F0.  Will this version have the functions we need?

                  • Re: Point Status 'L' Code
                    Abe Chandrabose

                    Hi Chris,

                     

                    The Min/Max functions were not implemented in the F0 firmware for the C3413 CPU, so it won't be available in the SAGE 2300.

                     

                    There is another option for the SAGE 2300 that will involve using the Calculation Processor and the Primary/Secondary IED Application.

                    Using the 4-20mA Hardware Analog that is scaled as 0 (EGU Min) to 28 (EGU Max) as an example, create one Calculation with Result Type of Analog, with one Input, and set the EGU Min to 0 and EGU Max to 28.  Create one Constant with a value of 0.0.  When you configure the Calculation point, set Input #1 to Type CON.  Click the Map Const button and map in the Constant of 0.0 that was created.

                    Go to the Primary/Secondary IED application, and create 1 IED Pair.  On the Primary/Secondary IED Configuration page, change the number of Analogs to 1, and click the Map button for Analogs.  In the Analog Input mapping page, map the 4-20mA Hardware Analog that is monitoring the MW output of the gen bus in the Primary Device, and map the Calculation point created in the previous step in the Secondary Device.  On the Primary/Secondary IED Configuration, set the Analog Health Point with a Failover Limit of 0 while the radio selection for Normal State is set to Above.  Click the Map button for the Analog Health Point, and map the 4-20mA Hardware Analog that is monitoring the MW output of the gen bus.  This configuration will allow the Primary/Secondary IED to use the Calculation result of 0.000 when the 4-20mA is below 0.000, and will switch to the 4-20mA Hardware Analog when it is at 0.001 or above.  The result of this configured Primary/Secondary IED pair will be an Analog Input source point that can be mapped to the ISO.

                     

                    Let us know if this solution works for you.

                     

                    Thank you,

                    Abe