VIPA SM 231 - Page 54

Chapter 2 Analog input modules Manual VIPA System 200V
2-30 HB97E - SM-AIO - Rev. 12/32
Analog values are exclusively processed in a binary format. For this the
analog module transforms every process signal into a digital value and
transfers this as word.
Resolution Analog value
byte 1 byte 0
Bit number 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Value SG 2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
12bit + sign
SG Measuring value A E O
The here listed formulas allow you to transform an evaluated measuring
value (digital value) to a value assigned to the measuring range and vice
versa.
Measuring range Current (I) Decimal (D) Hex Range Formulas for
calculation
24.00mA 2560 0A00h overrange
20mA 2048 0800h
12mA 1024 0400h
4mA 0 0000h
nominal range
4 ... 20mA
Siemens S5 format
0mA -512 FE00h underrange
16
4
2048
−
⋅=
I
D
4
2048
16
+⋅= DI
Order number 231-1BD60
Type SM 231
Current consumption/power loss
Current consumption from backplane bus 280 mA
Power loss 1.4 W
Technical data analog inputs
Number of inputs 4
Cable length, shielded 200 m
Rated load voltage -
Current consumption from load voltage L+ (without
load)
-
Voltage inputs -
Min. input resistance (voltage range) -
Input voltage ranges -
Operational limit of voltage ranges -
Basic error limit voltage ranges with SFU -
Current inputs
9
Max. input resistance (current range) 20 Ω
Input current ranges +4 mA ... +20 mA
Operational limit of current ranges -
Basic error limit current ranges with SFU -
Resistance inputs -
Resistance ranges -
Operational limit of resistor ranges -
Basic error limit -
Resistance thermometer inputs -
Resistance thermometer ranges -
Operational limit of resistance thermometer ranges -
Basic error limit thermoresistor ranges -
Representation of
analog values
Measuring value
Technical data