Emerson 8700 Series, Reference Manual

Page: 41 / 136

Reference Manual
00809-0100-4793, Rev CA
August 2004
Rosemount 8742C
4-2
Each F
OUNDATION
fieldbus configuration tool or host device has a different
way of displaying and performing configurations. Some will use Device
Descriptions (DD) and DD Methods to make configuring and displaying data
consistent across host platforms. There is no requirement that a configuration
tool or host support these features. This section describes how to reconfigure
the device manually.
QUICK START-UP
Once the magnetic flowmeter system is installed and communication is
established, configuration of the transmitter must be completed. The standard
transmitter configuration, without Option Code C1, Custom Configuration, is
shipped with the following parameters:
Flowtube
Calibration Number
A unique flowtube calibration number, imprinted on the flowtube tag, enables
any Rosemount flowtube to be used with any Rosemount transmitter without
further calibration. Rosemount flow lab tests determine individual flowtube
output characteristics. The characteristics are identified by a 16-digit
calibration number.
The 16-digit calibration number can be programmed into the Rosemount
8712D/H or 8732C transmitter using the Local Operator
Interface (LOI) or the 375 Field Communicator. Refer to the appropriate
transmitter product manual for complete instructions. In a F
OUNDATION
fieldbus environment, the 8742C can be configured using the DeltaV
™
configuration tool or another F
OUNDATION
fieldbus configuration device.
The calibration number is more than a correction factor, or K- factor, for the
flowtube. The first five digits represent the low frequency gain. The ninth
through thirteenth digits represent the high frequency gain. Both numbers are
normalized from an ideal number of 10000. Standard configurations use the
low frequency gain, but in noisy applications it may be worthwhile to switch to
the higher frequency. An additional transmitter procedure, called Auto Zero, is
required to perform at the higher coil drive frequency. The seventh and eighth
digits represent the zero offset at both frequencies where the nominal value
is 50. Empty pipe functionality is a transmitter feature that is controlled by a
parameter in the transducer block. To turn off this feature, see Section 4:
Operation and Maintenance, “Learning Empty Pipe” on page 4-5.
ASSIGNING DEVICE TAG
AND NODE ADDRESS
The 8742C Magnetic Flowmeter Transmitter is shipped with a blank tag and a
temporary address to allow a host to automatically assign an address and a
tag. If the tag or address need to be changed, use the features of the
configuration tool. The tools do the following:
• Change the tag to a new value.
• Change the address to a new address.
When the device is at a temporary address, only the tag and address can be
changed or written to. The resource, transducer, and function blocks are all
disabled.
Engineering Units: ft/s
Tube Size: 3-in.
Flowtube Calibration Number: 100000501000000