Danfoss HVAC Drive FC 102 Series Instructions Manual

Also see for VLT AQUA Drive FC 202: Service guide Installation guide Installation guide Operating guide Installation guide

Contents

2.2.4 Override/Override Release Commandsand Time Out, 8-04 (Setting [20], N2Override release)The way the overridden points are released is very importantto the way the drive will behave during the override releasetime out or for release commands issued by the N2 master.This is due to the fact that the active setup can be changed toa different setup. If one would release the active setup beforethe values that have been overridden in that setup, thebackup values would then be restored to the wrong setup,leaving the overridden values in the old setup unchanged.The release after override time out:During an override release time-out, all points which areoverridden, will be released in the order, which they arespecified in Appendix POINTMAP:1. Release Analog Outputs from point address (NPA) 0to 255.2. Release Binary Outputs from point address (NPA) 0to 255.3. Release Internal Floating Points from point address(NPA) 0 to 255.4. Release Internal Integer Points from point address(NPA) 0 to 255.5. Release Internal Byte points from point address(NPA) 0 to 255.2.2.5 Change of State (COS)/POLLINGA change of state occurs when a new command has beenissued for the drive. This command can be issued through thebus or through a drive related status change or command. Themaster can issue a series of poll commands to the networkdevices to get an update on any status changes from the timeof the last polling. When polling a frequency converter for thefirst time after a network has been powered up after an Fcommand has been issued, a 0/4 poll command must beissued.2.2.6 Handling of Poll Message CommandsThe Identity Command will cause the drive to report all AI, AO,BI and BO points, which are available when the next Poll (0/4)is received. The drive also supports COS for AI and BI pointtypes. The drive is limited to responding with up to 200 ASCIIcharacters, so multiple messages may need to be sent beforeall available points have been reported.Upon receiving the Poll (0/4), the frequency converter willbegin exporting the requested information. The frequencyconverter will continue to export new information uponreceiving the 0/5 Poll until it has sent all requested informa-tion. Then it will respond to a new 0/5 Poll with an ACKresponse to indicate all information has been transmitted andcomplete the Poll sequence receiving a 0/4 Poll beforesending the ACK response will cause the frequency converterto re-transmit its latest response.The drawing below illustrates the AI COS handling.Instructions VLT® Metasys16 MG.11.G2.02 - VLT® is a registered Danfoss trademark22