Reference Manual
00809-0100-4697, Rev EA
October 2011
Rosemount 848T
D-12
Indirect
Indirect signal conversion converts the signal linearly to the accessed
channel input value (or the simulated value when simulation is enabled)
from its specified ra nge (XD_SCALE) to the ra nge and unit s of the PV and
OUT parameters (OUT_SCALE).
Indirect Square Root
Indirect Square Root signal conversion takes the square root of the value
computed with the indire ct signal conversion and scales it to the range and
units of the PV and OUT parameters.
When the converted input value is below the limit specified by the LOW_CUT
parameter, and the Low Cutoff I/O option (IO_OPTS) is enabled (True), a
value of zero is used for the converted value (PV). This option is useful to
eliminate false readings when the differential temperature measurement is
close to zero, and it may also be useful with zero-based measurement
devices such as flowmeters.
NOTE
Low Cutoff is the only I/O option supported by the MAI block. Set the I/O
option in Manual or Out of Service mode only.
Block Errors
Table D-5 lists conditions reported in the BLOCK_ERR parameter. Conditions
in bold are inactive for the MAI block and ar e given for reference.
Table D-5. BLOCK_ERR
Conditions
PV Channel Value
100
---------------------------------------


EU**@100% EU**@0%–EU**@0%+=
** OUT_SCALE values
PV Channel Value
100
---------------------------------------


EU**@100% EU**@0%–EU**@0%+=
** OUT_SCALE values
Number Name and Description
0Other
1Block Configuration Error: the selected channel carries a measur ement that is
incompatible with the engineering units selected in XD_SCALE, the L_TYPE
parameter is not configured, or WRITE_CHECK = zero.
2Link Configuration Error
3Simulate Active: Simulation is enabled and the block is using a simulated value in
its execution.
4Local Override
5Device Fault State Set
6Device Needs Maintenance Soon
7Input Failure/Process Variable has Bad Status: The hardware is bad, or a bad
status is being simulated.
8Output Failure: The output is bad based primarily upon a bad input.
9Memory Failure
10 Lost Static Data
11 Lost NV Data
12 Readback Check Failed
13 Device Needs Maintenance Now
14 Power Up
15 Out of Service: The actual mode is out of service.