Trend Studies - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Johnson Controls
Product name
Controller Configuration Tool
Document type
User Guide
Document number
Revision date

If you are investigating the PID controller's ability to maintain control with either a custom or standard application, you can troubleshoot errors by creating a trend study. A trended item is a data point in the controller that is periodically sampled and logged. Use the Metasys Export Utility to collect the trend data, or simply collect and paste the data into a spreadsheet.

Examine the following parameters when you create your trend study:

  • Controlled Variable (for example, room temperature or discharge static pressure): Trend at intervals equal to the PID Eff Period
  • PID Setpoint: Trend using COV
  • PID Output: Trend at PID Eff Period
  • State of Output Control: Trend using COV

Additional parameters provide details on how the PID is using PRAC+ to adapt tuning parameters. However, investigating these additional parameters requires that you use the FC Bus Engineering View to find the BACnet® Object Identifier (BACoid), and then manually map the objects to include in a trend study. Make sure to trend these parameters:

  • PRAC Status: Trend using COV
  • Eff Proportional Band: Trend using COV
  • Eff Integral Time: Trend using COV