Pepperl+Fuchs KFD HM 16 Series Manual page 18

HART Multiplexer System KFD*-HM*-16
Product specification
3.3.5 HART Multiplexer Slave
Slave connection
3.3.6 Operation
18
The HART Multiplexer Slave is supplied from the HART Multiplexer Master via the
14-core flat cable. The contacting of the flat cable is provided via IDC connectors, so
that the cable can be tapped at any position. By this means, the power supply and
data cables are looped on from station to station. The address 1 ... 15 is set via a 16-
step rotary switch. Address 0 is reserved for the Multiplexer Master and must
therefore not be used. If a number of Slaves are operated on the KFD2-HMM-16,
different addresses must be assigned. The sequence therefore plays no role in this.
The analog signals are fed via a 26 core flat cable into the KFD0-HMS-16. 16 of
these are intended for the HART signal of the analog instrument circuit (the
remaining 10 are to ground) (for the assignment, see section 9.2).
The minimum load resistance of the analog measuring circuit is 230  (minimum
load impedance in accordance with HART specification), the maximum resistive load
being 500 . Load resistances of up to 1000  are possible, however, resistance
values greater than 500  can interfere with the HART communication.
Figure 3.7 Front view HART Multiplexer Slave
HART Multiplexer Masters and Slaves must be connected together via a separate K-
HM14 flat cable.
The length of cable required should be stated when ordering. Hence the wiring of the
HART Multiplexer is significantly simplified and the danger of wiring faults is
excluded.
The Multiplexer also functions as a HART device (see also section 5.4.5). However,
due to the incorporation into the operating software of the service station (see
section 3.3.3), this remains concealed from the user. The HART commands that are
supported by the Multiplexer can be found in section 9.1.
For HART communication with the transmitters, the commands of the service station
are passed through without modifications.
1
Rotary switch
26
26 pin
Connector
14 pin
Connector