Emerson Rosemount 3095, Справочное руководство, Страница: 109 / 130

Reference Manual
00809-0100-4716, Rev JA
May 2008
5-3
Rosemount 3095 MultiVariable
Overrange Conditions
Overrange conditions typically indicate an error that the sensor or flow
measurements have reached an overrange condition where substitute values
are being used.
Table 5-3 identifies actions to the analog output and digital output during
these conditions. Blank table cells indicate no action for that condition. Table
5-4 shows recommended corrective action, and also identifies effects on the
flow calculation during these conditions.
Table 5-3. Overrange Conditions.
EA Display
(Diagnostics,
Error Info)
Analog Output Digital Output
Flow DP AP/GP PT Flow Total Flow DP AP/GP PT
Flow
Total
DP above URL+
Saturate in
direction of
alarm jumper
Saturate
High
(1)
Saturate in
direction of
alarm jumper
URL+
DP below LRL–
Saturate
Low
(2)
Saturate
Low
(2)
Saturate
Low
(2)
zero URL– zero
AP/GP above
URL+
Saturate in
direction of
alarm jumper
Saturate in
direction of
alarm jumper
Saturate
High
(1)
Saturate in
direction of
alarm jumper
URL+ URL+
AP/GP below LRL–
Saturate in
direction of
alarm jumper
Saturate in
direction of
alarm jumper
Saturate
Low
(2)
Saturate in
direction of
alarm jumper
URL– URL–
PT above URL+
Saturate in
direction of
alarm jumper
Saturate
High
(1)
Saturate in
direction of
alarm jumper
URL+
PT below LRL–
Saturate in
direction of
alarm jumper
Saturate
Low
(2)
Saturate in
direction of
alarm jumper
URL–
ST above URL+ Saturate in direction of alarm jumper NAN
(3)
NAN
(3)
NAN
(3)
NAN
(3)
NAN
(3)
ST below LRL– Saturate in direction of alarm jumper NAN
(3))
NAN
(3)
NAN
(3)
NAN
(3)
NAN
(3)
(1) Saturate high if direct acting (URV>LRV), Saturate low if reverse acting (URV<LRV).
(2) Saturate low if direct acting (URV>LRV), Saturate high if reverse acting (URV<LRV).
(3) NAN indicates “Not a Number.” Distributed Control Systems and HART masters will read “7F A0 00 00h.”
Table 5-4. Corrective Action: Overrange Conditions
EA Display
(Diagnostics,
Error Info)
LCD Display
Flow Calculation Affects
(1)
Corrective Action
C’ ( )
0.5
“DP above URL+” “DP_OL” URL+ URL+
These displays indicate that the transmitter differential pressure reading exceeds its
sensor limits by more than 10%. There are two possible causes. Either the transmitter
is overpressured (underpressured), or it has a sensor malfunction. Check the
pressure input to the transmitter. If an overpressure (underpressure) condition exists,
correct it. If not, replace the sensor module as described on page 5-9.
“DP below LRL–” “DP_OL”
Unreliable
flow output
Unreliable
flow output
“AP/GP above
URL+ “
“SP_OL” UOL URL+
These displays indicate that the transmitter absolute pressure reading exceeds its
sensor limits by more than 10%. There are two possible causes. Either the transmitter
is overpressured (underpressured), or it has a sensor malfunction. Check the
pressure input to the transmitter. If an overpressure (underpressure) condition exists,
correct it. If not, replace the sensor module as described on page 5-10page 5-9
“AP/GP below
LRL–”
“SP_OL” LOL LRL–
“PT above URL+” “PT_OL” UOL URL+
Check the transmitter RTD connector and RTD screw terminals to ensure the RTD
cable is properly connected. Verify that the process temperature is between -300F
and 1500 °F. Check output board revision level to verify this is correct process
temperature range.
“PT below LRL– “ “PT_OL” LOL LRL–
“ST above URL+” no display
Unreliable
flow output
Unreliable
flow output
These displays indicate that the ambient temperature limit of the transmitter is being
exceeded. Verify that the transmitter ambient temperature is between -40F and 185F.
If transmitter temperature exceeds these limits, correct the temperature. If transmitter
temperature is within these limits, replace the sensor module as described on page 5-9.
“ST below LRL–” no display
Unreliable
flow output
Unreliable
flow output
(1) Only the parameter causing the exception is clipped at the operating or sensor limits. The other calculation inputs are not affected.