Beckhoff EPI4 Series, Documentation

Page: 61 / 82

Commissioning and configuration
EPI4xxx, ERI4xxx 61 Version: 1.6
5.7.2 Presentation, index 0x08n0:02
The measured value output is set in factory to two's complement representation (signed integer). Index
0x80n0:02 offers the possibility to change the method of representation of the measured value.
Signed integer representation
The negative output value is represented in two’s complement (n 1). Maximum representation range
for 16 bits = -32768…+32767
dec
Input signal Value
+/- 10 V 0…20 mA 4…20 mA 0…10 V Decimal hexadecimal
10 V 20 mA 20 mA 10 V 32767 0x7FFF
5 V 10 mA 12 mA 5 V 16383 0x3FFF
0 V 4 mA 4 mA 0 V 0 0x0000
-5 V - - - -16383 0xC001
-10 V - - - -32767 0x8000
Overview of further representations
• Unsigned integer representation
The output value is represented with 15-bit resolution without sign, therefore polarity detection is no
longer possible. Maximum representation range for 16 bits = 0…+32767
dec
• Absolute value with MSB as sign - representation
The output value is displayed in signed amount representation: MSB = 1 (highest bit) in the case of
negative values. Maximum representation range for 16 bits = -32768…+32767
dec
Input signal
(+/- 10 V) Unsigned integer representation Absolute value with MSB as sign - representation
dec hex dec hex
10 V 32767 0x7FFF 32767 0x7FFF
5 V 16383 0x3FFF 16383 0x3FFF
0 V 0 0x0000 0 0x0000
-5 V 16384 0x4000 [-16384] 0xC000
-10 V 32767 0x7FFF [-32767] 0xFFFF
Presentation types
The presentation types Unsigned integer and Absolute value with MSB as sign have no function for
unipolar modules. There is no change in the presentation in the positive range.
5.7.3 Siemens bits, index 0x08n0:05
If this bit is set, status displays are superimposed on the lowest three bits. Bit 0 is set in the event of an
Overrange or Underrange error.