Rosemount 8712, Reference Manual

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Reference Manual
00809-0100-4664, Rev BA
January 2010
Rosemount 8712
4-30
Quaternary Variable
The quaternary variable maps the fourth variable of the transmitter. This
variable is a HART only variable and can be read off of the HART signal with a
HART enabled input card, or can be burst for use with a HART Tri-Loop to
convert the HART signal to an analog output. Options available for mapping
to this variable are:
• Forward Gross
• Forward Net
• Reverse Gross
• Electronics Temp
Polling Address
Poll Address enables you to set the poll address for a multi- dropped meter.
The poll address is used to identify each meter on the multi-drop line. Follow
the on-screen instructions to set the address at a number from 1 to 15. To set
or change the flowmeter address, establish communication with the selected
Rosemount 8712 in the loop.
NOTE
The Rosemount 8712 is set to poll address zero at the factory, allowing it to
operate in the standard point-to-point manner with a 4–20 mA output signal.
To activate multidrop communication, the transmitter poll address must be
changed to a number between 1 and 15. This change deactivates the 4–20
mA analog output, setting it to 4 mA, and disables the failure mode alarm
signal.
Number of Request Preambles
This is the number of preambles required by the 8712 for Field
Communications.
Number of Response Preambles
This is the number of preambles sent by the 8712 in response to any host
request.
Burst Mode
Burst Mode Configuration
The Rosemount 8712 includes a burst mode function that broadcasts the
primary variable or all dynamic variables approximately three to four times a
second. The burst mode is a specialized function used in very specific
applications. The burst mode function enables you to select the variables to
broadcast while in the burst mode and to select the burst mode option.
The Burst Mode variable enables you to set the Burst Mode to the needs of
your application. Options for the Burst Mode setting include:
• Off–Turns off the Burst Mode so that no data are broadcast on the loop.
• On–Turns Burst Mode on so that the data selected under Burst Option
are broadcast over the loop.
Field Comm. 1, 4, 2, 7, 1, 2
Field Comm. 1, 4, 2, 7, 2
Field Comm. 1, 4, 2, 7, 3
Field Comm. 1, 4, 2, 7, 4
Field Comm. 1, 4, 2, 7, 5