Yokogawa ADMAG AXR - Manual (Page 80)

<6. PARAMETER DESCRIPTION>
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IM 01E30D01-01EN
(8) Menu J: Auxiliary Function Setting items
Menu J contains setting items such as the flow
direction, rate limits, and current output limits.
[J10: 4-20mA Low Cut] Setting of the low-cut
range for current output
This parameter is used to force current output to
0 % (i.e., 4 mA) in the vicinity of 0% output, and
setting for the current (4 to 20 mA) output low cut is
made using a percentage of the smallest flow rate
span.
The low cut setting value depends on flow rate
span.
● Flow rate span < 1 m/s:
Input value or 3 cm/s, whichever is bigger
● Flow rate span ≥ 1 m/s:
Input value
To confirm the flow rate span velocity in “m/s” unit,
see [C44: Velocity Check].
Example 1: Situation where the flow rate span is set
to 2 m/s:
When “10 %” is input in this parameter, low cut
setting value is to be “10 %”.
F0608.ai
Setting range: 0 to 20%
4mA
Output
Input 0.5% 0.5%
10%
10%
Setting value
Hysteresis
fixed at 1%
5.6mA(10%)
Example 2: Situation where the flow rate span is set
to 0.8 m/s:
When “3 %” is input in this parameter, low cut
setting value is to be “3 cm/s”.
F0608-2.ai
Setting range: 0~20%
4mA
Output
Input
0.5% 0.5%
3% 3cm/s
3cm/s
Input value:3%(=2.4cm/s)
Setting value
Hysteresis
fixed at 1%
4.6mA(3.75%)
If the multiple ranges or forward/reverse ranges is
used, low cut is carried out at the setting value for
the smallest span.
However, the low cut function will be terminated if
this parameter is set to 0 %.
The indications of the instantaneous flow rate (%,
Actual instantaneous flow rate, mA, Bar graph) on
the display unit are the same action.
NOTE
The default setting is 3%.
When the low cut is small, an incorrect output
may occur at the flow rate of zero. Use the
instrument with the default setting 3%. If the span
is small, the damping time is short or the fluid is
low conductivity, an incorrect output may occur
easily at the flow rate of zero.
[J11: 4-20mA Low Lmt] Setting of the low limit for
current output
This parameter is used to restrict low current
portions of current (4 to 20mA) output, and it is
initially set to -1.25%. Setting should be performed
when a higher value is required for the lower limit.
The indications of the instantaneous flow rates (%,
Actual instantaneous flow rate, mA, Bar graph) on
the display unit are the same action.
Example: Situation where low limit is set to 10%
F0609.ai
4mA
Output
Input
5.6mA(10%)
NOTE
When the low limit works, the display indicates
83:Fix Cur Wng as the warning.
NOTE
The set current output at each alarm function
becomes higher priority than set value at J11
when the alarm occurs.
The priority of this output is described below.
The process alarms and setting alarms are
available when “Yes” were selected at G26, G27,
G28, G29 and/or G31.
System alarm ( G20) >
Process alarm ( G25) >
Setting alarm ( G31) >
Low limit ( J11)
Example: “3.8mA” is set for G25
The current output is 3.8mA in spite of
setting any value at J11.