Siemens S5-135U/155U - Manual (Page 453)

9-71
System Manual
C79000-G8576-C199-06
Measuring range 500 mV; card with 31.25 ohm shunt
(6ES5 498-1AA51/AA71)
The 4 to 20 mA range is resolved to 2048 units at an interval of 512 to 2560.
If you require a representation from 0 to 2048, you must subtract 512 units by
software. Please note the following:
S
A broken wire signal cannot be emitted.
S
Detection of the overrange can be achieved by scanning bits 2 9 and 2 11 .
S
A broken wire can be detected with currents < 3 mA.
S
If you short-circuit the positive and negative terminals of the transducer
when using the 6ES5 498-1AA51 range card (for a two-wire transducer),
the current is limited to about 28 mA. Until the thermal current limiting
circuit responds in the range card (about 3 s), a short-circuit current of
approximately 250 mA flows; this sets the overflow bit for this duration
at all channels.
Units Input Cur-
t i A
Byte 0 Byte 1
rent in mA
7
S
6
2 11
5
2 10
4
2 9
3
2 8
2
2 7
1
2 6
0
2 5
7
2 4
6
2 3
5
2 2
4
2 1
3
2 0
2
A
1
E
0
OV
w 4096 w 32.000 0 1 1 1 1 1 1 1 1 1 1 1 1 0/1 0 1 Overflow
4095
3072
3071
2561 31.992
24.0
23.992
20.008
0
0
0
0
1
1
1
1
1
1
0
0
1
0
1
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
0/1
0/1
0/1
0/1
0
0
0
0
0
0
0
0
Overrange
Short-circuit with two-
wire transducer
2560
2048
512 20.0
16.0
4.0
0
0
0
1
1
0
0
0
0
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0/1
0/1
0/1
0
0
0
0
0
0 Rated range
511
384
383 3.992
3.0
2.992
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
1
0
1
1
0
1
1
0
1
1
0
1
1
0
1
1
0
1
1
0
1
0/1
0/1
0/1
0
0
0
0
0
0
Range
underflow
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0/1 0 0 Broken wire
A = Active bit
E = Error bit
OV = Overflow bit
S = Sign
Measured-Value
Representation for
Current Measuring
Ranges from 4 to
20 mA
Current Limiting
Analog Input/Output Modules