User guide

Overview
© Schneider Electric 2011 11
The DALI application has been specified for use with the DALI mostly for
the benefit of keeping DALI control separate from other lighting control
operations.
How OPC Data Access handles Lighting Type data
The Lighting Type group transmits integer values within the range of 0-
255 values. The OPC Data Access handles discrete and ramping
operations differently.
When messages are sent from the C-Bus OPC Server to the OPC
Client
The Lighting Type group levels are transmitted to OPC Client as discrete
values. For example, if the light level changes from 215 to 225, the value
transmitted is 225. When a Lighting Type group ramps the lighting values
over 8 seconds, the OPC server transmits the light levels changing
gradually over the 8 seconds to match the C-Bus ramping.
When messages are sent to the C-Bus OPC Server from the OPC
Client
The OPC Data Access interface translates OPC values in the following way.
If the OPC value is between 0 and 255, this value is converted the same
value in OPC. If the value is over 255, the value in the C-Bus group. If the
value is -2 or less, the value is reset to 0. If the value is -1, the value is set
to 255. This is because in OPC, -1 is equivalent to the local 'true' value,
which is treated as fully On.
There is no provision for sending a ramping command to the C-Bus
network. The best way to ramp lighting levels from an OPC Client is to
activate ramping using C-Bus scenes. In this way, only one control
message is sent via the OPC Data Access interface.
Quality of data and network transmission
The OPC Data Access interface evaluates the quality of information
coming from C-Gate and provides a quality rating on the OPC item values.
The C-Bus OPC Server also monitors the status of all C-Bus networks it is
configured to use, and provides this information through OPC Data
Access
Logging of Lighting Compatible data
The C-Bus OPC Server generates logging data during start/restart and
stopping event sequences as well as operational OPC transmission events.
A subset of the log information is displayed in the M ESSAGES tab. The full
log information can be read using the SmartInspect logging viewer. The
location of C-Bus OPC Server log files is at:
C:\Clipsal\CbusOpcServer\Logs, (by default) if the C-Bus OPC
Server is configured to log to files. Logs directly related to OPC Data
Access will contain the words 'OPC DA' in the text.