YOKOGAWA AXFA14G - 6.2 Zero Adjustment Using Display Unit Switches

<6. Operation>
59
IM 01E20A01-01EN
6. Operation
Afteryouhaveinstalledtheowtubeintotheprocess
piping, wired the input/output terminals, set up the
required parameters, and performed a pre-operation zero
adjustment,themagneticowmetershouldoutputan
accurateowsignalfromitsterminalsassoonasowof
theuidtobemeasuredbegins.Thissectiondescribes
zero adjustment and the corresponding procedures.
6.1 Pre-operation Zero
Adjustment
Zero adjustment is carried out to ensure that the output
forzeroowis0%(i.e.,4mA).Althoughadjustmentto
zero is performed at the manufacturing plant prior to
shipment, this procedure must be carried out once again
following the installation of piping in order to match the
magneticowmetertoitsoperatingconditions.
This section describes the zero adjustment procedure
using display unit switches from the converter. Also, it
can be operated using the BT200 Handheld Terminal.
Accordingly, one of these methods should be selected
and implemented.
IMPORTANT
• Zero adjustment should be carried out before
actual operation. Note that setting and update
functions cannot be carried out during this
procedure (i.e., for approximately 30 seconds).
• Zero adjustment should only be carried out when
theowtubehasbeenlledwithmeasurement
uidandtheuidvelocityiscompletelyzeroby
closing the valve.
• Eachtimethattheuidbeingmeasuredis
changed, it will be necessary for zero adjustment
tobecarriedoutforthenewuid.
6.2 Zero Adjustment Using
Display Unit Switches
The parameters for zero adjustment are B50/M10: Auto
Zero Exe (and either of these can be used to carry out
this procedure). The parameter M10: Auto Zero Exe will
be used in the following description.
F0601.ai
Setting mode
Major item
parameter
Once in Setting Mode,
use the
switch to
move the cursor to M:
Adjustment.
Touch the
switch
to access Sub-item
Parameter Search Mode.
F0602.ai
Major item
Sub-item
selection (D)
M:Adjustment
10:Auto Zero Exe
11:Magflow Zero
Upon selection of M:
Adjustment, the cursor
will be positioned at M10:
Auto Zero Exe. (Sub-item
selection (D))
Touch the
switch
to access Parameter
Replacement Mode.
F0603.ai
Touch the switch
to move the cursor to
“Execution”.
F0604.ai
Touch the switch
toselectthe“Execution”.
F0605.ai
In order to request
conrmation,theentire
displayashesonand
off. Touch the
switch once again at
thistimetoxselection
of the automatic zero
adjustment function.
NOTE
When no operations are carried out for 20 seconds in
theashingstate,thesystemwillautomaticallyreturn
to the Sub-item Parameter Search Mode.
When the operations except
switch are carried
out, the parameter cannot be set.
F0606.ai
Now Auto Zero
Executing...
Auto zero adjustment
function is being
executed
(about 30 seconds).
F0607.ai
Major item
Sub-item
selection (D)
M:Adjustment
10:Auto Zero Exe
11:Magflow Zero
When zero adjustment
function has been
completed, the system
automatically returns to
the sub-item selection
screen (D).
NOTE
Theresultsof“M10:AutoZeroExe”canbedisplayed
using“M11:MagowZero”.Alternatively,ifthe
results of the automatic zero adjustment exceed the
ratedvalue,thewarning“82:AutoZero”Wngwillbe
displayed.
Operation
6