Emerson Rosemount 644 Reference Manual page 8

Introduction
March 2021
• Optional advanced LCD display with local operator interface (LOI)
• The Rosemount 644 Head Mount Transmitter is available in two housing materials
(Aluminum and SST) and various housing options that allow for mounting flexibility in a
variety of environmental conditions. The Rosemount 644 Field Mount is available in an
aluminum housing.
• Special dual-sensor features include Hot Backup
differential and average temperature measurements, and four simultaneous
measurement variable outputs in addition to the analog output signal.
• Additional advanced features include: Thermocouple degradation diagnostic, which
monitors thermocouple health, and process and transmitter minimum/maximum
temperature tracking.
The Rosemount 644 Rail Mount Temperature Transmitter supports the following features:
• 4–20 mA/HART protocol (Revision 5)
• Accepts one sensor input from a wide variety of sensor types (2-, 3-, and 4-wire RTD,
Thermocouple, mV and ohm)
• Completely encapsulated electronics to ensure long term transmitter reliability
Refer to the following literature for a full range of compatible connection heads, sensors,
and thermowells provided by Emerson.
• Rosemount Volume 1 Temperature Sensors and Accessories (English)
Sheet
• Rosemount DIN-Style Temperature Sensors and Thermowells (Metric)
Sheet
Table 1-1
Rail Mount HART device revisions, respectively.
Table 1-1: Head Mount HART Revisions
Software
release date
Feb-2020
Aug-2012
(1) NAMUR Software Revision is located in the hardware tag of the device. HART Software Revision
can be read using a HART-capable configuration tool.
(2) Device Driver file names use Device and DD Revision ( e.g. 10_07). HART Protocol is designed to
enable legacy driver revisions to continue to communicate with new HART devices. To access this
functionality, the new device driver must be downloaded. It is recommended to download the
new device driver to ensure new functionality.
8
and Table 1-2 below summarize changes in the Rosemount 644 Head Mount and
Identify device
NAMUR NAMUR
software hardware
revision revision
1.1.xx 1.0.xx
1.1.xx 1.0.xx
™
, Sensor Drift Alert, first good,
Field device driver
HART HART
software universal
(1)
revision revision
7
4
5
3 7
Reference Manual
00809-0200-4728
Product Data
Product Data
Review
instructions
Manual
Device
document
revision
(2)
number
9
00809-0200-
4728
8
00809-0200-
9
4728
Emerson.com/Rosemount