|Product technical data|
RT communication is not absolutely necessary to operate the ESK II.If HART communication is carried out with the ESK II,it will not impair analog data transmission (4-20mA) in any way.An exception is the Multidrop mode,when a maximum of 15 devices with HART function can be operated in parallel,in whitch case their current outputs are switched to inactive mode (I approx. 4mA).
When a HART communication (Type Fisher Rosemount,Model 275) or a PC with HART modem is used,the series-connected resistance (Rext.) needs to be greater than 250 Ohm.The supply power must in this case be at least 18 V.The communicator or PC is connected as shown in the above drawing.It can optionally be operated via the supply terminals of the ESK II or via a series-connected external resistor.
The HART communicator can be operated either in hazardous or in non-hazardous locations.For application in hazardous areas a transmitter feeder unit with HART/smart capability is required,e.g.KFD2-STC3-Ex1 supplied by P+F.
When the ESK II is operated in conjunction with the ESK-Z totalizer,HART communication is possible in accordance with the following connection diagram:The totalizer cannot be read out or set by the HART communication.