Installation Instructions

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Siemens Desigo Room automation - Engineering, mounting and installation CM111043en_14
Smart Infrastructure Electrical features of inputs & outputs 2020-10-30
8 Electrical features of inputs & outputs
8.1 Digital inputs
Digital inputs are not electrically isolated from the system electronics.
Mechanical contacts must be volt-free.
Electronic switches must comply with SELV or PELV standards.
Technical data
Contact sensing voltage DC 17...25 V
Contact sensing current 1.0...1.6 mA (initial current 6...10 mA)
Insulation resistance with
contacts closed
Max. 200 Ohm (TX-I/O)
Max. 100 Ohm (DXR2)
Contact resistance with contacts open Min. 50kΩ
8.2 Analog inputs
8.2.1 Passive resistance sensors
The temperature sensors register the temperature by means of a nickel or platinum
wire or a semiconductor which change their resistance in relation to the
temperature.
Key:
R Sensor signal (resistance)
T Actual temperature
The table below shows the resistance of the supported sensor elements as a
function of the temperature.
Temp
AI Ni1000
AI Ni1000
AI Pt1K375
AI Pt1K385
AI T1
AI NTC100K
AI NTC10K
TCR 5000
(
LG
-
Ni 1000)
DIN
TCR 3750
(USA)
TCR 3850
(Europe)
(PTC)
Beta 3891
Ratio 9.062
Beta 3890
Ratio 9.065
EN60751
°C °F Ohm Ohm Ohm Ohm *) kOhm kOhm
-
40
-
40
830.8
791.3
846.6
842.7
1'840.4
336.487
-30 -22 871.7 841.5 885.1 882.2 1'934.6 176.974
-
20
-
4
913.5
893.0
923.5
921.6
2'030.3
97.080
-
10
14
956.2
945.8
961.8
960.9
2'127.6
552.830
55.332
0
32
1'000.0
1'000.0
1'000.0
1'000.0
2'226.4
326.329
32.650
10
50
1'044.8
1'056.0
1'038.0
1'039.0
2'326.9
198.958
19.904
20 68 1'090.7 1'112.0 1'076.0 1'077.9 2'429.1 124.920 12.494
30
86
1'137.6
1'171.0
1'113.8
1'116.7
2'532.9
80.567
8.057
40
104
1'185.7
1'230.0
1'151.4
1'155.4
2'638.5
53.256
5.326
50
122
1'235.0
1'291.0
1'189.0
1'194.0
2'745.9
36.010
3.602
60
140
1'285.4
1353.4
1'226.4
1'232.4
2'855.1
24.864
2.488
70
158
1'337.2
1417.2
1'263.8
1'270.8
2'966.2
17.505
1.752
Typical sensing
current
1.1 1.1 1.1 1.1 1.1 0.16 0.7
*) Not measurable with ohm meter
Supported only with reduced hum injection (details see 7.1.2)
Measured value
acquisition and
measured signal
Resistance table