Siemens S5-155U System Manual page 422

The 463 Analog Input Module
Setting the data format for
the 4 to 20 mA range
Connecting transducers
9 - 50
When using the 4 to 20 mA inputs, you can select data representation
of 0 to 1023 bits or 256 to 1279 bits by pressing the appropriate
switch. You can choose different data formats for all four input
channels.
When the voltage or 0 to 20 mA inputs are used, the relevant switches
remain at the opposite settings.
Labelling of the switch on the module cover:
range 4 ... 20 mA
0 ... 1023
range 4 ... 20 mA
256 ... 1279
other ranges
0 ...1023
1)
It is advisable to mark the selected switch setting in these fields.
Transducers are connected to the analog input module via shielded
cables of up to 200 m in length. When they are laid separately from
power system cables, distances of up to 500 m are possible.
An arbitrary mixture of voltage sensor, current sensor, two-wire and
four-wire transducers can be connected. For two-wire transducers,
there are four short-circuit protected supply terminals at the front
connector.
Caution
To use two-wire transducers, the reference potential (common
input) of these channels must be connected to L-. This defeats the
isolation between the channels and the supply voltage L+/L-.
Note that the bus interface of the module is activated with 24 V via
enable lines F+ and F- at the front connector.
channel 0
channel 1
channel 2
channel 3
1)
channel 3
channel 2
channel 1
channel 0
System Manual
C79000-B8576-C109-03