Danfoss VLT DriveMotor FCP 106 Programming Manual

Also see for VLT DriveMotor FCM 106: Operating instructions Operating instructions Design guide Design guide Installation instructions

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Danfoss VLT DriveMotor FCP 106 Programming Manual Manual pdf 29 page image

NOTICEThe motor current in 16-14 Motor current is 32 bit. Thismapping is only mapping the lower 16 bit, so themaximum motor current readout is 327 Amps.For higher Amp readout, user 32 bit readout.Mapping a 32 bit parameter as 16 bit always accesses the16 lower bits.3.8.11 How to Control the FrequencyConverterThis section describes codes which can be used in thefunction and data fields of a Modbus RTU message.3.8.12 Function Codes Supported byModbus RTUModbus RTU supports use of the following function codesin the function field of a message.Function Function codeRead coils 1 HexRead holding registers 3 HexWrite single coil 5 HexWrite single register 6 HexWrite multiple coils F HexWrite multiple registers 10 HexGet comm. event counter B HexReport follower ID 11 HexRead write multiple registers 17 HexTable 3.14 Function CodesFunction FunctionCodeSub-functioncodeSub-functionDiagnostics 8 1 Restart communication2 Return diagnostic register10 Clear counters anddiagnostic register11 Return bus message count12 Return bus communi-cation error count13 Return follower errorcount14 Return follower messagecountTable 3.15 Function Codes3.8.13 Modbus Exception CodesFor a full explanation of the structure of an exception coderesponse, refer to chapter 3.8.5 Function Field.Code Name Meaning1 IllegalfunctionThe function code received in the query isnot an allowable action for the server (orfollower). This may be because thefunction code is only applicable to newerdevices, and was not implemented in theunit selected. It could also indicate thatthe server (or follower) is in the wrongstate to process a request of this type, forexample because it is not configured andis being asked to return register values.2 Illegal dataaddressThe data address received in the query isnot an allowable address for the server(or follower). More specifically, thecombination of reference number andtransfer length is invalid. For a controllerwith 100 registers, a request with offset96 and length 4 would succeed, a requestwith offset 96 and length 5 generatesexception 02.3 Illegal datavalueA value contained in the query data fieldis not an allowable value for server (orfollower). This indicates a fault in thestructure of the remainder of a complexrequest, such as that the implied length isincorrect. It specifically does NOT meanthat a data item submitted for storage ina register has a value outside theexpectation of the application program,since the Modbus protocol is unaware ofthe significance of any particular value ofany particular register.4 Followerdevice failureAn unrecoverable error occurred while theserver (or follower) was attempting toperform the requested action.Table 3.16 Modbus Exception Codes3.9 How to Access Parameters3.9.1 Parameter HandlingThe PNU (Parameter Number) is translated from theregister address contained in the Modbus read or writemessage. The parameter number is translated to Modbusas (10 x parameter number) DECIMAL. Example: Reading3-12 Catch up/slow Down Value (16bit): The holding register3120 holds the parameters value. A value of 1352(Decimal), means that the parameter is set to 12.52%RS-485 Installation and Set... VLT® DriveMotor FCP 106 and FCM 106 Programming GuideMG03N102 - Rev. 2013-12-02 273 3