turck BL20 Series - 17.1.1 Equations for 16-bit representation

495
2020/09
17.1.1 Equations for 16-bit representation
Current values from 0 to 20 mA
Before using the equation below, the hexadecimal or binary value has to be converted into a deci-
mal value.
The value range:
0…20 mA
is displayed as follows:
0000
hex
…7FFF
hex
(decimal: 0…32767)
The hexadecimal/binary value can easily be converted into a decimal value, because all numbers
belong to the positive range of the two’s complement.
The current value can now be calculated by means of the following equation:
Current values from 4…20 mA
Before using the equation below, the hexadecimal or binary value has to be converted into a deci-
mal value.
The value range:
4…20 mA
is displayed as follows:
0000
hex
…7FFF
hex
(decimal: 0…32767)
The hexadecimal/binary value can easily be converted into a decimal value, because all numbers
belong to the positive range of the two’s complement.
The current value can now be calculated by means of the following equation:
current value = 4.88 × 10
-4
mA × decimal value + 4 mA
Temperature- and resistance values (BL20-2AI-PT/NI-2/3)
Before using the equation below, the hexadecimal or binary value has to be converted into a deci-
mal value.
The hexadecimal/binary values for the negative value range cannot easily be converted into deci-
mal values, because the values are coded as two’s complement.
All numerical values from 00000
hex…
7FFF
hex
represent positive values when coded as two’s com-
plement. Values in this range can easily be converted into decimal values. This is also relevant for
binary numbers in which the most significant bit (bit 16) is ”0”.
All numerical values from 8000
hex
to FFFF
hex
represent negative values when coded as two’s com-
plement. This is also relevant for binary numbers in which the most significant bit (bit 16) is ”1”. The
conversion into a decimal number is shown in the following:
value decimalmA
4
106.1mA
1638.35
value decimal
valuecurrent 
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