turck BL67 - Analog Value Representation (Analog Output Modules); Resolution of Analog Value Representations; Equations for 16 Bit Representation

Appendix
D300529 0115 - BL67 I/O modules15-22
15.3 Analog value representation (analog output modules)
15.3.1 Resolution of analog value representations
In the bipolar mode the digitalized analog values are represented as a two’s complement. The 16 bit or
the 12-bit-representation (left justified) can be chosen by setting the respective module parameter.
15.3.2 Equations for 16 bit representation
Current values from 0 to 20 mA
The decimal values for the current values from 0 mA to 20 mA can be calculated by means of the fol-
lowing equation:
decimal value = 1638,35
1
mA
--------
× current value
The value range:
0 mA to 20 mA
is displayed as follows:
0000
hex
to 7FFF
hex
(decimal: 0 to 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
(→ page 15-9).
Current values from 4 to 20 mA
The decimal values for the current values from 4 mA to 20 mA can be calculated by means of the fol-
lowing equation:
decimal value = 2047,9375
1
mA
--------
× current value - 8191,75
The value range:
4 mA to 20 mA
is displayed as follows:
0000
hex
to 7FFF
hex
(decimal: 0 to 32767)
The decimal value can easily be converted into a hexadecimal value, because all numbers belong to the
positive range of
the two’s complement (→ page 15-9).
Voltage values from 0 to 10 V DC
The decimal values can be converted into current values from 0 VDC to 10 VDC by means of the follow-
ing equation:
decimal value = 3276,7
1
V
---
× voltage value
The decimal value can easily be converted into a hexadecimal value, because all numbers belong to the
positive range of
the two’s complement (→ page 15-9).
Voltage values from -10 to 10 V DC