Emerson Rosemount 644h, Reference Manual

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Reference Manual
00809-0100-4728, Rev HA
December 2002
4-9
Models 644H and 644R
LCD Display
In addition to the output, the LCD display displays abbreviated diagnostic
messages for troubleshooting the transmitter. To determine the cause of a
message, use a Model 275 HART Communicator to further interrogate the
transmitter. A description of each diagnostic message is identified in
Table 4-3. The device sometimes requires additional interrogation to
determine the source of the warning. Contact Emerson Process Management
Customer Central at (800) 999-9307 for further information.
Table 4-3. LCD Display
Diagnostics
Value out of range The user-entered value is either not within the range for the given type and size of variable or
not within the min/max specified by the device.
<message> occurred reading/writing
<variable label> Either a read/write command indicates too few data bytes received, transmitter fault, invalid
response code, invalid response command, invalid reply data field, or failed pre- or post-read
method; or a response code of any class other than SUCCESS is returned reading a
particular variable.
<variable label> has an unknown value.
Unit must be sent before editing, or invalid
data will be sent. A variable related to this variable has been edited. Send related variable to the device before
editing this variable.
Message Description
ALARM
Description
DEV FAIL The top line of the display scrolls through the following three messages:
• “BAD”
• “DEV”
• “FAIL”
This message indicates one of several conditions. For example, the transmitter may have experienced an electronics
failure while attempting to store information. If diagnostics indicate an electronics failure, replace the transmitter with a
new one. Contact the nearest Emerson Process Management Field Service Center if necessary.
SNSR FAIL The top line of the display scrolls through the following three messages:
• “BAD”
• “SNSR”
• “FAIL”
The bottom line display s the name of the sensor that has failed. This message indicates that the transmitter has detected
an open or shorted sensor condition. The sensor may be disconnected, connected improperly, or malfunctioning. Check
the sensor connections and sensor continuity.
UNCRN The top line of the display alternates between “UNCRN” and the sensor value. The bottom line will display the name of the
sensor for which this message applies. The uncertain message is displayed when the sensor reading is outside of the
acceptable temperature range for the particular sensor type.
FIXED During a loop test or a a 4–20 mA output trim, the analog output defaults to a fixed value. The top line of the display
alternates between “FIXED” and the amount of current selected in milliamperes. The bottom line will hold on “AO mA.”
OFLOW The location of the decimal point, as configured in the meter setup, is not compatible wit the value to be displayed by the
meter. For example, if the meter is measuring a process temperature greater than 9.9999 degrees and the meter decimal
point is set to 4-digit precision, the meter will display an “OFLOW” message because it is only capable of displaying a
maximum of 9.9999 when set to 4-digit precision.
ALARM When a failure occurs and the meter is configured to display Primary Variable Percent of Range and/or Analog Output, the
top line o the meter will display “ALARM.” This indicates that the transmitter is in failure mode.
SAT When the transmitter output saturates and the meter is configured to display Primary Variable Percent of Range and/or
Analog Output, the top line of the meter will display “SAT.” This indicates that the transmitter output has reached
saturation level.