Dcf77 Receiving Service; Antenna; Location Selection; Orientation To The Transmitter - Siemens SICLOCK DCFRS Betriebsanleitung

User Manual SICLOCK DCFRS for WINCC

2.2 DCF77 receiving service

Installation of the DCF77 receiving service (driver software) should be done before the antenna is
erected, since the antenna can be operated and orientated towards the transmitter only using the
software. Installation of the software for the Windows NT and Windows 95 operating systems is
described in the enclosed installation instructions. On completion of installation the DCF77 receiving
service awaits the time signals of the antenna at the selected interface.

2.3 Antenna

2.3.1 Location Selection

Antenna erection should be preceded by careful selection of the location. It has a decisive effect on
the reception quality and thus on the availability of the DCF77 time signal. It can be at a maximum
distance of 20 m from the PC with the installed receiving service. The following criteria should be
optimised in the selection:
• Distance to electrical devices :
which degrades reception. Therefore the antenna should be set up as far away as possible from
electrical devices. Particularly high disturbance levels are exhibited by monitors, PCs, laser printers,
motor drives, etc. and therefore these devices should be at maximum distance. It should also be noted
that the antenna cable should not be laid parallel to power cables (e.g. power supply cables for
motors).
• Screening:
reception quality. Therefore, as great a distance as possible should be maintained from metallic
objects. It is also important to note that the steel reinforcement contained in reinforced concrete will
weaken the field under certain circumstances. Therefore the antenna should not be screwed directly
onto metallic surfaces using the enclosed angle mount.
•

Orientation to the Transmitter:

located near Frankfurt in Germany. Steel incorporated in modern buildings weakens the reception
signal. For optimum reception the reception location should be selected preferable on the side towards
Frankfurt. In addition the antenna should be erected as high as possible..
In most cases naturally not all of these recommendations can be fulfilled optimally. However it is
important to ensure that none of the criteria are seriously transgressed (e.g. location of the antenna
near a monitor). If the reception results are unsatisfactory, the selected antenna location should be
checked again carefully. In addition to the antenna location, the antenna orientation to the transmitter
has decisive significance in achieving the maximum reception quality.
2.3.2 Orientation to the transmitter
As with a radio or television antenna, the DCF77 reception antenna must be orientated towards the
transmitter. To assess the reception quality an LED is located on the antenna which lights up briefly
every second if reception is faultless. For orientation purposes the antenna should be first connected
with the PC where the DCF77 receiving service was installed and started. The erection assembly
permits erection parallel or vertical to the earth's surface.
Order No. 2XV9450-1AR17
Each electrical device transmits electromagnetic radiation
Metallic objects screen the reception signal and degrade
The transmitter which transmits the DCF77 time signal is
Version 1.0 5