Analog Inputs
Original instructions
Overview
This section describes how to interpret the value of the analog input channels.
Key
This section describes input words 1 ... 8, as highlighted in the table below:
Word
Input Data
Output Data
1
Value, input channel 1
Parameters for input channels 1 ... 4
2
Value, input channel 2
Parameters for input channels 5 ... 8
3
Value, input channel 3
Not used
4
Value, input channel 4
Not used
5
Value, input channel 5
Not used
6
Value, input channel 6
Not used
7
Value, input channel 7
Not used
8
Value, input channel 8
Not used
Bit Assignments
The following table tells how bits are assigned:
Analog-to-digital conversion
Carried out on 14 bits + sign for bipolar input ranges,15 bits for unipolar ranges
Bit 15
Sign bit
Bits 14 ... 0
Input channel values
Analog Input Values
Mapping of analog input values is shown below.
Broken Wire Indication
Broken wire detection is possible for the 4 ... 20 mA range. In this case, a current signal that is less than 1 mA on one of the inputs is detected as a broken wire. The input word of that channel returns the signed value -32,768. A broken wire indication has the following binary format: