CARLO GAVAZZI EM 21, Руководство по протоколу связи

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Energy management
EM24-DIN Communication Protocol
7
2 TABLES
2.1 Data format representation In Carlo Gavazzi instruments
The variables are represented by integers or floating numbers, with 2’s complement notation in case of
“signed” format, using the following:
Format IEC data type Description Bits Range
INT16 INT Integer 16 -32768 .. 32767
UINT16 UINT Unsigned integer 16 0 .. 65535
INT32 DINT Double integer 32 -2
31
.. 2
31
UINT32 UDINT Unsigned double int 32 0 .. 2
32
-1
UINT64 ULINT Unsigned long integer 64 0 .. 2
64
-1
IEEE754 SP Single-precision floating-
point 32 -(1+[1 –2
-23
])x2
127
.. 2
128
For all the formats the byte order (inside the single word) is MSB->LSB. In INT32, UINT32 and UINT64
formats, the word order is LSW-> MSW.
2.1.1 Geometric representation
According to the signs of the power factor , the active power P and the reactive power Q, it is possible to
obtain a geometric representation of the power vector, as indicated in the drawing below, according to
EN 60253-23:
Fig. 2 : Geometric Representation
a = Exported active power
b = Imported active power
c = Imported reactive power
d = Exported reactive power
2.2 Maximum and minimum electrical values in EM21
The maximum electrical input values are reported in the following table. If the input is above the
maximum value the display shows “----”.
Table 2.1-1
AV5 input option AV6 input option
Max value Min value Max value Min value
VL-N 485V 0 150V 0
VL-L 840V 0 260V 0
A 6,5A 0 6,5A 0
VT 6000 1.0 6000 1.0
CT 60000 1.0 60000 1.0
The overflow indication “----“ is displayed when the MSB value of the relevant variable is 7FFFh.