SATEC SLC500 - Manual (Page 9)

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° Examples:
1. The phase A reactive power of value 130,750 kvar is transferred as:
word 34 = 750
word 35 = 13
word 36 = 0
The actual value is 13*10000 + 750 = 130,750
2. The phase A reactive power of value -130,750 kvar is transferred as:
word 34 = 750
word 35 = 13
word 36 = 1
The actual value is - (13*10000 + 750) = -130,750
Total active power is transferred only for positive values. In the case of the negative total
power, the value will be zeroed.
4.1.3 Data Set #3
In data set #3, values are transferred as signed integers in the range of -32768 to +32767. The
sign is transferred as a high bit of an integer value. In the case of the negative value being
scaled down and transferred in two words, both the high and low words will be negative
integers.
° Examples:
1. The reactive power A of value 130,750 kvar is transferred as:
word 27 = 750
word 28 = 13
The actual value is 13*10000 + 750 = 130,750
2. The reactive power A of value 130,750 kvar is transferred as:
word 27 = -750
word 28 = -13
The actual value is (-13)*10000 + (-750) = -130,750
4.1.4 Error Reporting
The status of the instrument being polled is always reported in word 64 of the M1 file. When
reading the M1 file, the CPU should check this word before applying data. The value of 0
shows the data in the M1 file is OK. When the BASIC module fails to receive data from the
instrument, a non-zero error code is written to word 64 accompanied by the instrument
address in word 1. All other words will be zeroes. The possible error code values are shown in
Table 4-1.