9.10
Optimization of the power supply (supply by the adapter)
Parameters to be optimized
If you use field devices that are supplied by the adapter, it may be necessary to optimize
settings for the power supply.
Parameter
Meaning
Example
Default
Start-up voltage
Voltage in volts that the connected field device
requires in the range 8 ... 23 V in steps of 0.1 V
14 V
16 V
Start-up time
Time in seconds during which the field device
requires the "start-up voltage".
5 s
5 s
Start-up current
Current in milliamperes required by the field de‐
vice for the "start-up time".
14 mA
14 mA
Operating voltage
Voltage in volts that the field device requires in
normal operation after the "start-up time".
12 V
16 V
Lead time
Time in seconds after the "start-up time" that the
field device requires to provide valid measured
values.
10 s
10 s
Optimum parameter settings
Note
Multidrop mode
If power supply of a field device takes place via the adapter, we recommend that you operate
the field device in multidrop mode. This mode keeps the power output more or less constant at
4 mA so that less energy will be consumed than with active power output.
Note
Reduced battery life
The power supply of a field device with the adapter reduces the life of the adapter battery.
Depending on the set parameters and the environmental conditions, battery life may be less
than one year.
The adapter constantly calculates the expected battery life and indicates the remaining life
users can expect. You can read out the currently anticipated battery life with a configuration tool.
The following table lists the ideal power supply settings for Siemens field devices:
Parameter
Field devices
Start-up time
Start-up voltage Start-up current Operating volt‐
age
Lead time
SITRANS P DSIII
15 s
12 V
3.55 mA
10.5 V
300 s
SITRANS P300
15 s
12 V
3.55 mA
10.5 V
300 s
SITRANS TF (with TH300 V1)
2 s
13.5 V
3 mA
13.5 V
0 s
SITRANS TH300 V2
2.5 s
12 V
3 mA
12 V
0 s
Parameter assignment/addressing
9.10 Optimization of the power supply (supply by the adapter)
WirelessHART Adapter SITRANS AW200
Operating Instructions, 02/2020, A5E02777161-AA
61
