39
Service Instructions
MAN-02-08-77-0714-EN Rev. 2
September 2020
Section 5: Communication Protocols
Communication Protocols
5.2 HART
The EHO actuators are capable of offering HART7 communication protocol over the widely
used 4-20 mA analog channels. The HART CAM interface board certified by the Fieldcom
group (previously HART Communication Foundation or HCF) is capable of offering Point-
to-Point, Multi-drop and WirelessHART communication topologies. Networks may extend
up to 3000 meters with Point-to-Point topology; and from 250 meters to 2000 meters
when 1 to 10 devices are connected using Multi-drop topology. The WirelessHART
supports up to 100 devices when connected to one Emerson Gateway, extending the
number of devices when multiple Emerson Gateways are installed.
Table 6.
HART Pin Connections
STC PINS
HART CONNECTIONS
41
HART 0+ (AO+)
42
HART 0- (AO-)
43
HART I+
44
HART I-
24
Shield
Figure 24
HART Topology