electroplating production process monitoring
parameters are abstracted and stored in the XML data
model, and then the UML function model diagram of
XML layer function class is constructed. As shown in
Figure 3, the XML_Base class has the ability to create
XML, add node parameters, and query node
parameters. In the figure, class XML_Craft refers to
electroplating process parameter, XML_Trough
parameter, XML_Bath parameter and XML_Monit
parameter refer to electroplating production process
monitoring parameter. All of these XML data classes
are derived from the XML_Base class. The blocks
and arrows in the diagram show the relationships and
extensions in UML rules.
Figure 3: UML Diagram of XML layer functional class.
5 DATA COLLECTION OF
ELECTROPLATING
PRODUCTION PROCESS
The OPC server is used for data exchange, and the
OPC server uses the Siemens CP5621
communication card, because CP5621 supports many
types of fieldbus protocols, which can be used to
collect various protocol data. It contains the
corresponding communication program and data
storage program, and provides standard OPC
interface for communication. The schematic diagram
of the hardware structure of the data acquisition layer
is shown in Figure 4. According to the three types of
objects of the OPC server, OPC is divided into three
layers: OPC Server, OPC Grop and OPC Item: the
top-level OPC Server has all the information of the
server, and the OPC Grop group is set under it. Grop
group provides a way for users to organize data, users
can read and write it, and can also set the data update
rate of the client, and when the data in the server
buffer changes, OPC will send a notification to the
user, and the user will be notified Then do the
necessary processing without wasting a lot of time
querying. There is also an OPC Item group under
OPC Grop, which points to a register unit of the
device. By defining data items, the special
information of the device is hidden in the OPC
specification to enhance the versatility of the OPC
server. Since OPC Item does not define external
interface, it is accessed through OPC group. OPC
Item contains attributes such as value, quality,
timestamp, etc. The data value is expressed in the
form of VARIANT, which simply describes the data
address. In order to greatly simplify the data structure
and improve the transmission efficiency, the protocol
specified by OPC is used for data interaction with the
upper layer, so that switching between multiple
protocols can be eliminated. And due to the large
amount of data involved in the electroplating
production process, the use of synchronous
communication will cause delays, so asynchronous
communication is selected to complete the data
exchange.
Figure 4: Schematic diagram of hardware structure of data
acquisition layer.
5.1 Write Plating Process Parameters
How to write the electroplating process parameters
into the electroplating production process is the key
to realizing the digitization of the electroplating
production process. Different process parameters
need to be configured in the application layer
according to different process conditions, such as
production process control parameters and coating
quality control parameters need to be configured
separately. It also needs to go through various
operation processes such as conversion, parsing,
storage, and transmission, and finally complete the
parameter writing.