Fieldbus control 297Feedback from the drive – EFB Pre-defined feedbackInputs to the controller (drive outputs) have pre-defined meanings established by theprotocol. This feedback does not require drive configuration. The following table listsa sample of feedback data. For a complete listing, see input word/point/object listingsin the technical data for the appropriate protocol starting on 302.Note: With Modbus, any parameter can be accessed using the format: 4 followed bythe parameter number. Mailbox Read/WriteThe ACS320 provides a “Mailbox” function to access parameters that have not beenpre-defined by the protocol. Using mailbox, any drive parameter can be identified andread. Mailbox can also be used to adjust parameter settings by writing a value to anyparameter identified. The following table describes the use of this function.1.As noted above, Modbus provides direct access to all parameters using the format: 4 followed by theparameter number.Drive Parameter Protocol ReferenceModbus N2 FLN BACnet0102 SPEED 40102 AI3 5 AV00103 FREQ OUTPUT 40103 AI1 2 AV10104 CURRENT 40104 AI4 6 AV40105 TORQUE 40105 AI5 7 AV50106 POWER 40106 AI6 8 AV60107 DC BUS VOLT 40107 AI11 13 AV20109 OUTPUT VOLTAGE 40109 AI12 14 AV30115 KWH COUNTER 40115 AI8 10 AV8Name Description Protocol ReferenceModbus1 N2 FLN BACnetMailboxParameterEnter the number of the driveparameter to access.Does notapply.AO19 95 AV25MailboxDataContains the parameter value after aread, or enter the desired parametervalue for a write.AO20 96 AV26MailboxReadA binary value triggers a read – thevalue of the “Mailbox Parameter”appears in “Mailbox data”.BO19 97 BV15MailboxWrite A binary value triggers a write – thedrive value for the “Mailbox Parameter”changes to the value in “Mailbox data”.BO20 98 BV16
