Emerson Rosemount 848T, Reference Manual, Page: 62 / 136

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Reference Manual
00809-0100-4697, Rev GA
Section 4: Operation and Maintenance
November 2014
Operation and Maintenance
Table 4-1. Block Diagram for the Rosemount 848T
4.2.1 Commissioning (addressing)
To be able to setup, configure, and have it communicate with other devices on a segment, a
device must be assigned a permanent address. Unless requested otherwise, it is assigned a
temporary address when shipped from the factory.
If there are two or more devices on a segment with the same address, the first device to start up
will use the assigned address (ex. Address 20). Each of the other devices will be given one of the
four available temporary addresses. If a temporary address is not available, the device will be
unavailable until a temporary address becomes available.
Use the host system documentation to commission a device and assign a permanent address.
4.3 Hardware maintenance
The 848T has no moving parts and requires a minimal amount of scheduled maintenance. If a
malfunction is suspected, check for an external cause before performing the diagnostics
presented below.
4.3.1 Sensor check
To determine whether the sensor is causing the malfunction, connect a sensor calibrator or
simulator locally at the transmitter. Consult an Emerson Process Management
representative for additional temperature sensor and accessory assistance.
4.3.2 Communication/power check
If the transmitter does not communicate or provides an erratic output, check for adequate
voltage to the transmitter. The transmitter requires between 9.0 and 32.0 VDC at the terminals
to operate with complete functionality. Check for wire shorts, open circuits, and multiple
grounds.
F
OUNDATION
fieldbus
Communications
Stack
Analog-to-Digital
Signal Conversion
Cold Junction
Input-to-Output
Isolation
Resource
Block
•physical
device
information
Function Blocks
•AI, MAI, and ISEL
Transducer Block
Measurement Sensor
•sensor and differential
temp
•terminal temp.
•sensor configuration
•calibration
•diagnostics
(8 sensors)