Tag Page
The Tag page (figure 34) is the page displayed when entering configuration mode. The tag page allows
the user to view and modify the tag, descriptor, message, final assembly number, date and polling
address.
•
Tag:
is a user-entered value. It may be up to 8 characters long and is used to identify the valve
within a plant. HART can use the tag to verify that it is communicating to the desired valve.
•
Descriptor:
A description with up to 16 characters for the device or application.
•
Message:
is a user-entered value. It may be up to 32 characters long and may contain any
text the user wishes.
•
Final Assembly Number:
This field contains a user-entered number. When the SVI is mounted on
a valve and installed in the field, the user can assign the assembly a unique number for their
internal use.
•
Date:
This field contains a user entered date value with the format DD/MM/YY. The value is stored
inside the device. It can be used however the user wishes and is often used to track the date of the
last valve maintenance.
•
Polling Address:
HART can communicate with up to 15 devices on a single pair of wires. These
devices are distinguished by their polling addresses, which are numbers from 0 to 15. If there is a
device at polling address 0, it must be the only device on the loop. There may be up to 15 devices
with non-zero polling addresses on the loop (subject to power and intrinsic safety constraints).
Devices which operate 4-20 mA are generally required to have polling address 0, however with split
range valve positioners, several 4-20 mA devices may be wired in series. These devices should be
set up with non-zero polling addresses.
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Figure 34. SVI Configuration - Tag Window
