Rosemount 4500, Reference Manual

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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