Danfoss VLT FC 102 Series Design Manual

Also see for VLT HVAC Drive FC 102: Operating instructions Service guide Programming guide Installation guide Installation guide

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8.4.10 Parameter Value (PWE)The parameter value block consists of two words (fourbytes), and the value depends on the defined command(AK). The master prompts for a parameter value when thePWE block contains no value. To change a parameter value(write), write the new value in the PWE block and sendfrom the master to the follower.When a follower responds to a parameter request (readcommand), the present parameter value in the PWE blockis transferred and returned to the master. If a parametercontains not a numerical value, but several data options,e.g., 0-01 Language where [0] is English, and [4] is Danish,select the data value by entering the value in the PWEblock. See Example - Selecting a data value. Serialcommunication is only capable of reading parameterscontaining data type 9 (text string).15-40 FC Type to 15-53 Power Card Serial Number containdata type 9.For example, read the unit size and AC line voltage rangein 15-40 FC Type. When a text string is transferred (read),the length of the message is variable, and the texts are ofdifferent lengths. The message length is defined in thesecond byte of the message, LGE. When using text transferthe index character indicates whether it is a read or a writecommand.To read a text via the PWE block, set the parametercommand (AK) to ’F’ Hex. The index character high-bytemust be “4”.Some parameters contain text that can be written to viathe serial bus. To write a text via the PWE block, set theparameter command (AK) to ’F’ Hex. The index charactershigh-byte must be “5”.PWE high PWE lowRead textWrite text130BA275.10PKE INDFx xx 04 00Fx xx 05 00Figure 8.11 Text via PWE Block8.4.11 Data Types Supported by theAdjustable Frequency DriveUnsigned means that there is no operational sign in themessage.Data types Description3 Integer 164 Integer 325 Unsigned 86 Unsigned 167 Unsigned 329 Text string10 Byte string13 Time difference33 Reserved35 Bit sequenceTable 8.8 Data Types and Description8.4.12 ConversionThe various attributes of each parameter are displayed infactory setting. Parameter values are transferred as wholenumbers only. Conversion factors are therefore used totransfer decimals.4-12 Motor Speed Low Limit [Hz] has a conversion factor of0.1. To preset the minimum frequency to 10 Hz, transferthe value 100. A conversion factor of 0.1 means that thevalue transferred is multiplied by 0.1. The value 100 istherefore read as 10.0.Examples:0 s ⇒ conversion index 00.00 s ⇒ conversion index -20 ms ⇒ conversion index -30.00 ms ⇒ conversion index -5Installation and Set-up Design Guide152 Danfoss A/S © Rev. 06/2014 All rights reserved. MG11BC2288