
BRONKHORST®
Page10DeviceNetinterface 9.17.026
Thedistancebetweenanytwopointsmustnotexceedthemaximumcabledistanceallowedforthedatarateused.
Datarate
Maximumdistance
(flatcable)
Maximum distance
(thickcable)
Maximum distance
(midcable)
Maximumdistance
(thincable)
125kbit/s 420m 500m 300m 100m
250kbit/s 200m 250m 250m 100m
500kbit/s 75m 100m 100m 100m
2.5 DROPLINESWITHDEVICENET
Thecumulativedroplinelengthreferstothesumofalldroplines,thick,thin,ormidcable,inthecablesystem.This
sumcannotexceedthemaximumcumulativelengthallowedforthedatarateused.
Datarate Cumulativedroplinelength
125kbit/s 156m
250kbit/s 78m
500kbit/s 39m
Themaximumcabledistancefromanydeviceonabranchingdroplinetothetrunklineis6m.
2.6 NETWORKTERMINATION
Youmustterminatethetrunklineatbothendswith121Ohms,1%,1/4Wterminatingresistors.
2.7 POWERSUPPLY
Thecablesystemrequiresthepowersupplytohavearisetimeoflessthan250millisecondstowithin5%ofitsrated
outputvoltage.Youshouldverifythefollowing:
Thepowersupplyhasitsowncurrentlimitprotection
Fuseprotectionisprovidedforeachsegmentofthe
cablesystem
Anysectionleadingawayfromapowersupplymusthaveprotection
Thepowersupplyissizedcorrectlytoprovideeachdevicewithits
Requiredpower
De‐ratethesupplyfortemperatureusingthemanufacturer’sguidelines
UsethepowersupplytopowertheDeviceNetcablesystemonly.Ifadevicerequiresaseparate24V
powersourceotherthantheDeviceNetpowersource,youshoulduseanadditional24Vpowersource.
ChoosingaPowerSupply
Thetotalofallofthefollowingfactorsmustnotexceed3.25%ofthenominal24VneededforaDeviceNetsystem.
initialpowersupplysetting 1.00%
lineregulation 0.30%
temperaturedrift(total) 0.60%
timedrift 1.05%
loadregulation 0.30%
Themaximumcabledistanceisnotnecessarilythetrunklengthonly.Itisthemaximumdistance
betweenanytwodevices.
Kommentare zu diesen Handbüchern