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Manual Supplement
00809-0500-4530, Rev AA
October 2010
1-9
Rosemount 5300/5400 Series
External HART Devices
(Slaves)
The HMC supports up to four external HART devices. The external devices
are separated by using the HART address. The address must be different
between the external devices and only addresses 1 to 5 are allowed for
multiple slaves. Connect the devices one at a time and change the short
address prior to connecting the next device by using a HART Configuration
Tool such as RRM, or a Field Communicator.
NOTE
The power supply from the HMC to external HART devices is not intrinsically
safe. In a hazardous environment, any external HART device connected to
the HMC must have Flameproof/Explosion-proof certification.
The HMC cyclically polls the HART devices for measurement values. The
update rate depends on the number of connected devices and is shown in
Table 1-2.
Table 1-2. Approximate update
rates for measurement values
Figure 1-7. The HMC Module
supports up to four external devices
(slaves)
No. of devices
(slaves)
Approx. update rate
1 2 seconds
2 3 seconds
3 4 seconds
4 5 seconds
5 5 seconds
MODBUS
POWER
HART
(RS-485)
HART to Modbus Converter
MB
MA
-
-
+
+
Ambients > 60 ºC
Use wiring rated
for min 90 ºC
Power
Supply
RS-485
Bus
Up to four
external
devices
External HART
device 2
External HART
device 1