Emerson 4500 User Manual

Page of 70
Reference Manual 
00809-0100-4027, Rev AA
December 2005
3-23
Rosemount 4500
AMS
Right click on the device and select “Configuration Properties” from the menu
.
1. In the “HART” tab, use the drop down menu to select “Burst Mode ON or 
OFF.” For “Burst option” select the desired properties from the drop down 
menu. Burst options are as follows: 
PV
% range/current
Process vars/crnt
Process variables
2. After selecting options click Apply.
3. An “Apply Parameter Modification” screen appears, enter desired 
information and click OK.
4. After carefully reading the warning provided, select OK.
MULTIDROP 
COMMUNICATION 
Multidropping transmitters refers to the connection of several transmitters to a 
single communications transmission line. Communication between the host 
and the transmitters takes place digitally with the analog output of the 
transmitters deactivated. Up to fifteen transmitters can be connected on a 
single twisted pair of wires, or over leased phone lines.
Multidrop installation requires consideration of the update rate necessary from 
each transmitter, the combination of transmitter models, and the length of the 
transmission line. Communication with transmitters can be accomplished with 
Bell 202 modems and a host implementing HART protocol. Each transmitter 
is identified by a unique address (1–15) and responds to the commands 
defined in the HART protocol. HART Communicators and AMS can test, 
configure, and format a multidropped transmitter the same way as a 
transmitter in a standard point-to-point installation.
Figure 3-3 shows a typical multidrop network. This figure is not intended as an 
installation diagram. 
NOTE
A transmitter in multidrop mode has the analog output fixed at 4 mA. If a 
display is installed to a transmitter in multidrop mode, it will alternate the 
display between “current fixed” and the specified meter output(s).
Figure 3-3. Typical Multidrop 
Network
Power 
Supply
Bell 202 
Modem
RS-232-C
4500-05_AA.EP
S