Analog electronic modules
4.2 Analog value representation
ET 200S
4-2 Manual, Edition 10/2005, A5E00514527-01
Measured Values in the Event of Wire Break Dependent on Enabled Diagnostics
For the measuring range tables
• 1 V to 5 V, 4 mA to 20 mA
• Temperature sensor Pt xxx Standard and Climatic, Ni xx Standard and Climatic, Cu 10
Standard and Climatic
• Thermocouple type E, N, J, K, L, S, R, B, C, T
the following supplements and rules apply:
Table 4-1 Measured Values in the Event of Wire Break Dependent on Enabled Diagnostics
Measured values
Format Parameter assignment
Decimal Hexadecimal
Description
• Enable "wire break" diagnosis (at 1 V
to 5 V, 4 mA to 20 mA, RTD)
1
32767 7FFF
H
• Diagnostics message "wire break"
• Enable "wire break test" diagnostics
(with TC)
32767 7FFF
H
• Diagnostics message "wire break"
• "Wire break" diagnostics disabled (at
1 to 5 V, 4 to 20 mA, RTD)
1
• "Overflow/underflow" diagnostics
enabled
-32767 8000
H
• Measured value after leaving the
undershoot range
• "Value under low limit" diagnostic
message
• "Wire break" diagnostics disabled (at
1 to 5 V, 4 to 20 mA, RTD)
1
• "Overflow/underflow" diagnostics
disabled
-32767 8000
H
• Measured value after leaving the
undershoot range
S7
• "Wire break test" diagnostics disabled
(with TC)
--- ---
• Open input: Undefined measured
value
1
Measured value limits for wire-break and undershoot detection:
1 to 5 V: at 0.296 V
4 mA to 20 mA: at 1.185 mA
4.2.2 Analog Value Representation for Measuring Ranges with SIMATIC S7
Analog value representation
With the same nominal range, the digitized analog value is the same for input and output
values. Analog values are represented in two's complement.
The following table shows the analog value representation of the analog electronics
modules.
Table 4-2 Analog Value Representation (SIMATIC S7 Format)
Resolution Analog Value
Bit number 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Significance of the bits S 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
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