Yokogawa Value Series FX1000 - Manual (Page 98)

Measurement Channels and
Alarms
IM 04L21B01-01EN
3-25
3
2
1
4
5
6
7
8
9
10
11
12
13
14
App
Index
Examples of power measurement expressions are given below.
• Example 1: Active power
Expression
Channel Expression Unit Description
101 WATP W Active power (W)
• Example 2: Voltage 1
Expression
Channel Expression Unit Description
101 VOL1 V Input voltage (V) of
voltage 1
• Example 3: Current 1
Expression
Channel Expression Unit Description
101 CUR1 A Input current (A) of
current 1
• Example 4: Active energy
The following is an example of active energy that is calculated with a certain number
of significant digits. When the active energy reaches the maximum value that can
be indicated with the available number of digits, the value wraps around, like a
commercial energy meter. In this example the active energy is calculated in the range
of 0000.000 [kWh] to 9999.999 [kWh]. When the active energy reaches 9999.999 [kWh],
it is restarted from 0000.000 [kWh].
Expression
Channel Expression Unit Span Description
101 _WATP_*K01 (User-
specified)
0000.000
to
9999.999
The low-cut power (kW)
102 CARRY(K02):TLOG.
SUM(101)
kWh 0000.000
to
9999.999
The active energy that wraps
around at a certain value (kWh)
Constant
Constant Number Value Description
K01 0.001 Constant used to convert the value to kW
K02 10000 Threshold value to reset
TLOG Settings
Channel Timer No. Sum Scale Reset Description
102 (User-
specified)
/h Off This is the sum scale. When settings are
reset, this is set to Off.
Note
When you are performing an electric energy measurement that uses TLOG, use one of the
following methods to ensure that a computation overflow does not occur. When a computation
overflow occurs, the value is not automatically reset.
• Use the CARRY operator so that the value will be reset when it exceeds a specified value (see
example 4).
• Reset the value at the specified time.
In this situation, change the settings in example 4 as shown below.
Operator: Remove the CARRY operator from channel 102.
TLOG settings: Specify the timer number, and turn reset on. Use the timer settings for
the timer specified in the TLOG settings to specify when the value will be reset (see
section 7.1).
3.12 Measuring Power (/PWR1 Option)