228 ACS550-02/U2 User’s ManualEmbedded fieldbusFor example:Diagnostics – EFBFault queue for drive diagnosticsFor general ACS550 diagnostics information, see chapter Diagnostics on page 273.The three most recent ACS550 faults are reported to the fieldbus as defined below.Serial communication diagnosticsNetwork problems can be caused by multiple sources. Some of these sources are:• loose connections• incorrect wiring (including swapped wires)• bad grounding• duplicate station numbers• incorrect setup of drives or other devices on the network.The major diagnostic features for fault tracing on an EFB network include Group 53:EFB PROTOCOL parameters 5306…5309. Section Complete parameterdescriptions on page 128 describes these parameters in detail.FeedbackintegerParameterresolutionValue of theparameter thatdefines 100%(Feedback integer) · (Parameter resolution) ·(Value of 100% ref.) / 100% = Scaled value10 0.1% 1500 rpm1 10 · 0.1% · 1500 RPM / 100% = 15 rpm100 0.1% 500 Hz2 100 · 0.1% · 500 Hz / 100% = 50 Hz1 Assuming, for the sake of this example, that the Actual Value uses parameter 9908 MOT NOM SPEEDas the 100% reference and that 9908 = 1500 rpm.2 Assuming, for the sake of this example, that the Actual Value uses parameter 9907 MOT NOM FREQas the 100% reference and that 9907 = 500 Hz.Drive parameter Modbus protocol referenceABB DRV DCU PROFILE0401 LAST FAULT 404010412 PREVIOUS FAULT 1 404120413 PREVIOUS FAULT 2 40413Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com