Hitachi Relion 670 Series Applications Manual page 89

1MRK511407-UUS Rev. N
receiving the Analog scale factor over CFG-2 should divide the received scale factor by 10 and then
apply it to the corresponding analog data value.
• CFG-3 frame: The field ANSCALE (8 bytes) specifies the conversion factor as X' = M * X + B where;
M is magnitude scaling in 32 bit floating point (first 4 bytes) and B is the offset in 32 bit floating point
(last 4 bytes).
The server uses CFG-3 scale factor to scale the analog data values. As a result, the clients which use
scale factors in CFG-3 in order to recalculate analog values, will get a better resolution than using the
scale factors in CFG-2.
The following examples show how the scale factor is calculated.
Example 1:
AnalogXRange =
IECEQUATION2446 V1 EN-US
The scale factor is calculated as follows:
sc alefactor
IECEQUATION2447 V1 EN-US
The scale factor will be sent as 1 on configuration frame 2, and 0.1 on configuration frame 3. The range
of analog values that can be transmitted in this case is -0.1 to -3276.8 and +0.1 to +3276.7.
Example 2:
AnalogXRange =
IECEQUATION2448 V1 EN-US
The scale factor is calculated as follows:
sc alefac tor
IECEQUATION2449 V1 EN-US
The scale factor will be sent as 1 on configuration frame 2, and 0.15 on configuration frame 3. The range
of analog values that can be transmitted in this case is -0.15 to -4915.5 and +0.15 to +4915.5.
Example 3:
Analo gXRange =
IECEQUATION2450 V1 EN-US
The scale factor is calculated as follows:
sc alefac tor
IECEQUATION2451 V1 EN-US
The scale factor will be sent as 3051804 on configuration frame 2, and 305180.43 on configuration frame
3. The range of analog values that can be transmitted in this case is -305181 to -10000000000 and
+305181 to +10000000000.
Phasor measurement unit RES670
Application manual
3277.0
´
(3277.0 2.0 )
= =
0.1 a nd
65535.0
4915.5
´
(4915.5 2.0 )
= =
0.15 a nd
65535.0
10000000000
´
(10000000000 2.0)
= =
65535.5
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=
offse t 0.0
=
offse t 0.0
=
305180.43 a nd offse t 0.0
Section 6
Wide area measurement system
83