Emerson Rosemount 848T, Reference Manual, Page: 129 / 136

119
Reference Manual
00809-0100-4697, Rev GA
Appendix D: Function Blocks
November 2014
Function Blocks
Figure D-7. Input Selector Function Block Application Example (SEL_TYPE = average)
AVG_USE = 6
D.3.2 ISEL block troubleshooting
To determine OUT for a 6-input reading, read all eight, sort in numerical order, drop
the highest and lowest values, and calculate the average.
Symptom Possible causes Corrective action
Mode will not leave
OOS
Target mode not set Set target mode to something other than OOS.
Configuration error BLOCK_ERR will show the configuration error bit set. SELECT_TYPE must be
set to a valid value and cannot be left at 0.
Resource block The actual mode of the Resource block is OOS. See Resource Block
Diagnostics for corrective action.
Schedule Block is not scheduled and therefore cannot execute to go to Target Mode.
Typically, BLOCK_ERR will show “Power-Up” for all blocks that are not
scheduled. Schedule the block to execute.
Status of output is
BAD
Inputs All inputs have Bad status
OP selected OP_SELECT is not set to 0 (or it is linked to an input that is not 0), and it points
to an input that is Bad.
Min good The number of Good inputs is less than MIN_GOOD.
Block is in OOS
mode
Change mode to Auto
Block alarms will
not work.
Features FEATURES_SEL in the resource block does not have Alerts enabled. Enable
the Alerts bit.
Notification LIM_NOTIFY in the resource block is not high enough. Set equal to
MAX_NOTIFY.
Status Options STATUS_OPTS has Propagate Fault Forward bit set. This should be cleared to
cause an alarm to occur.
Cannot set
HI_LIMIT,
HI_HI_LIMIT,
LO_LIMIT,
LO_LO_LIMIT
Scaling Limit values are outside the OUT_SCALE.EU0 and OUT_SCALE.EU100 values.
Change OUT_SCALE or set values within range.
IN1 = 126 °F
IN2 = 118 °F
IN3 = 104 °F
IN4 = 107 °F
OUT = 118 °F
To Another
Function Block
SEL_TYPE = avg
Input Selector
(ISEL) Function
Block
IN5 = 112 °F
IN6 = 115 °F
IN7 = 130 °F
IN8 = 140 °F
AVG_USE = 6
107 112 115 118 126 130 + + + + +
6
----------------------------------------------------------------------------------------------- 118
°
F =