User Manual

Siemens Building Technologies CM2N8882en / 02.2000
Landis & Staefa Division 5/8
Switching points are digital output information points. Any status changes result from
operator input and program processes.
Switching points are also referred to as switching command points or digital output (DO)
points.
On the plant-side, the switching points consist of:
•
One or several electrically switchable elements such as a switching contactor for
pumps, fans, etc.
•
Optional feedback contacts confirming the switching processes
Additionally, switching points also have a remote/local function which acts on the module
in parallel to the auto/manual hand switches.
In VISONIK, switching command output and feedback message acquisition occurs via
the P-bus and the switching modules or a combination of switching and signalling
modules. The feedback message acts on a switching command and is automatically
tested.
SB
RM
1 2
VISONIK BPS
bidirectional
data line
Switching points
with feedback
from the plant
P-bus
Communication
partner
Preparation
Processing
8882Z05E
Switchin
g
module
Depending on the programming, switching command changes may trigger the following
functions in VISONIK:
Function Example
Reports Point status report
Switching status time count Operating hours count for one or several
switching steps
Maintenance reaction Reaching the operating hours limit
Acquiring the frequency of a specific
switching status
Operation analyses
Conduction of logical links between switching
and feedback information
Plant supervision such as fan ON,
feedback pressure sensor, etc
Triggering further switching commands due
to process and link controls
Controlled start-up of a plant, e.g.,
following power return
Transfer of information to various
communication partners
See "Transfer of module point
information", page 7.
Switching points
Definition
Design
Switching module
processing
Functions