Welker OdorEyes ECOsystem Pulse Bypass System Installation, Operation And Maintenance Manual page 36

Figure 32: Gas Flow Signal – Input Signal Setup
If the gas flow signal will be analog, the analog signal must be 4–20 mA powered by the user.
If the gas flow signal will be a pulse, the pulse will be a digital pulse powered by the controller.
If the pulse input method is selected, the Pulse Input Cutoff must also be set (Figure 33).
36 IOM-181 | MODEL: ECOSYSTEM™ WITH XLT CONTROLLER | REV: C 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department: 281.491.2331