Troubleshooting The Analog Input (Ai) Block; Table 26: Analog Input Block - Honeywell SLG 700 Option Manual

Troubleshooting the Analog Input (AI) block

Problem cause
Analog Input block
mode is in OOS and
does not change to
AUTO mode.
Analog Input block
mode is in OOS mode
with Block Configuration
Error.
Value of output seems
wrong.
Process and block
alarms do not work.
Cannot set alarm limits.
Rev.5
Table 29: Analog Input block
Things to check
Read
MODE_BLOCK.PERMIT
TED
Read MODE_BLOCK.
ACTUAL of Resource
block.
Read WRITE_LOCK
parameter in resource
block. Check if device is
in Write Protect mode.
If WRITE_LOCK =
Locked (2)
Schedule
Read CHANNEL
parameter and range.
Read L_TYPE
parameter.
Check if L_TYPE= Direct
Read Linearization Type.
Read Scaling.
Read FEATURE_SEL.
Read LIM_NOTIFY
Read Alarm Summary
Disable.
Read Scaling.
FOUNDATION Fieldbus Option User's Manual
Recommended action
Add AUTO mode to
MODE_BLOCK.PERMITTED.
If necessary, Set MODE_BLOCK.TARGET
to AUTO.
NOTE:
If the mode is set to OOS for maintenance,
then do not change the mode to AUTO.
Change Write Protect jumper to "W" position.
(See section 7.7)
Reset the device. (Cycle power to transmitter
or write "Processor" to RESTART parameter
in Resource block.)
Block is not scheduled and therefore cannot
execute to go to Target Mode. Schedule the
block to execute.
CHANNEL must be set to a valid value and
cannot be left at the initial value of zero.
XD_SCALE.UNITS_INDX must be
compatible with the units in the transducer
block for the channel.
L_TYPE must be set to Direct, Indirect, or
Indirect Square Root and cannot be left at
the initial value of zero.
When L_TYPE = Direct, XD_SCALE and
OUT_SCALE must contain the same range
values (EU_0 and EU_100).
Check the L_TYPE setting.
Check XD_SCALE and OUT_SCALE
Reports are not selected in FEATURE_SEL.
If features do not include Reports then the
host must poll for alarms.
Set LIM_NOTIFY to a value higher than
zero, but not higher than MAX_NOTIFY.
Check that process and block alarms are not
disabled.
Limit values are outside the
OUT_SCALE.EU_0 and
OUT_SCALE.EU_100 values. Set values
within range.
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