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Reference Manual
00809-0100-4027, Rev AA
December 2005
Rosemount 4500
3-24
The 4500 is set to address zero (0) at the factory, which allows operation in
the standard point-to-point manner with a 4–20 mA output signal. To activate
multidrop communication, the transmitter address must be changed to a
number from 1 to 15. This change deactivates the 4–20 mA analog output,
sending it to 4 mA. It also disables the failure mode alarm signal, which is
controlled by the upscale/downscale switch position. Failure signals in
multidropped transmitters are communicated through HART messages.
Changing a Transmitter
Address
To activate multidrop communication, the transmitter poll address must be
assigned a number from 1 to 15, and each transmitter in a multidropped loop
must have a unique poll address.
HART Communicator
1. From the HOME screen, enter the fast key sequence for “Changing a
Transmitter Address.”
AMS
Right click on the device and select “Configuration Properties” from the menu
.
1. In the “HART” tab, in “ID” box, enter poll address located in the “Poll
addr” box, click Apply.
2. An “Apply Parameter Modification” screen appears, enter desired
information and click OK.
3. After carefully reading the warning provided, select OK.
Communicating with a
Multidropped
Transmitter
HART Communicator
To communicate with a multidropped transmitter, configure the HART
Communicator to poll for a non-zero address.
1. From the HOME screen, enter the fast key sequence for
“Communicating with a Multidropped Transmitter.”
2. On the polling menu, scroll down and select “Digital Poll.” In this mode,
the HART Communicator automatically polls for devices at addresses
0-15 upon start up.
AMS
Click on the HART modem icon and select “Scan All Devices.”
Polling a Multidropped
Transmitter
Polling a multidropped loop determines the model, address, and number of
transmitters on the given loop.
HART Communicator
1. From the HOME screen, enter the fast key sequence for “Polling a
Multidropped Transmitter.”
AMS
Click on the HART modem icon and select “Scan All Devices.”
Fast Keys
1, 4, 3, 3, 1
Fast Keys
Left arrow, 4, 1, 1
Fast Keys
Left arrow, 4, 1