Data Sheet for Product

Technical Specification Sheet
Document No. 154-114
November 27, 2012
Siemens Industry, Inc. Page 1 of 4
GAMMA
Weather Station (GPS) AP 257
Description
The Weather Station WS1 (GPS) Advanced AP 257/22
and Basic AP 257/32 contain all sensors, electronic
systems for weather data analysis, and the Bus
Terminal in a single, compact enclosure.
Many features of the Weather Station WS1 (GPS)
Advanced AP 257/22 and Basic AP 257/32 are the
same. Throughout the rest of this document, Weather
Station AP 257 is used to refer to both models.
Advanced AP 257/22 or Basic AP 257/32 is used when
a specific model is being discussed.
The Weather Station AP 257 measures wind speed,
brightness and temperature, detects dusk/dawn and
precipitation, and receives the GPS signal for date and
time. In addition to date and time, all measured values
can be sent to the bus in the EIS5 (DPT 9) format and
each can be monitored with up to three limit values.
Limit values can be selected as parameters or as
communication objects.
The Weather Station AP 257 provides simple solar
protection control, which activates or deactivates the
solar protection depending on whether or not the sun
is shining. In addition, it can activate solar protection
control for up to four facades with consideration for
their alignment with the compass directions. In this
case, solar protection is automatically activated when
the sun shines on the facade and is deactivated when
sunlight no longer strikes the facade or after the sun
has set.
• If a building has more than four facades, use an
additional Basic AP 257/32, or use an Advanced
AP 257/22, which can control up to eight façades.
• If a building has more than eight facades, an
additional Weather Station AP 257 is
recommended, especially since the wind speed
can then also be measured at another point.
When monitoring conditions for multiple buildings, one
Weather Station AP 257 is recommended for each
building since different wind speeds can arise,
depending on the location of the buildings with respect
to one another.
In addition to the wind alarm, frost alarm, and
precipitation alarm, a total of up to eight alarms or error
messages can be combined using a logical OR
function to create a Safety communication object. In
case of an alarm, the solar protection is moved into its
safety position.
Four AND-gates and four OR-gates with four inputs
each are available for additional logic operations.
The Weather Station AP 257 may be used where GPS
reception is not possible. In this case, the date and
time must be sent to the device through the bus.
The Weather Station AP 257 electronics are powered
from a local 20 Vac NEC Class 2 transformer or 24
Vdc power supply. If powered from the Power Supply
Unit N 125/21 auxiliary output, a second twisted pair or
bus cable can be used.