Campbell Scientific CSIOPC Software - Manual (Page 10)

CSIOPCServer
Note that data must be collected from a datalogger and stored in the LoggerNet
data cache before that data will be available to OPC clients. Use LoggerNet's
Setup screen client to define the data tables to be collected and the schedule on
which the data should be stored in the data cache.
4. Identifying Data Values
4.1 Data Tags
A data tag is a text-based identifier for a specific data value that is being
passed from the LoggerNet communications server to an OPC client via the
CSIOPCServer. When a control in the OPC client is set up to display a data
value from a datalogger, the OPC client uses the data tag to request the
information from CSIOPCServer. Data tags used by CSIOPCServer are
defined using a combination of the device name in the LoggerNet device map
and data table and field names contained in the datalogger program. Data tags
take the form of:
CSIOPCServer.device_name.table_name.field_name
where device_name is the name of the datalogger in LoggerNet's network map,
table_name is the name of the table in the datalogger program, and field_name
is the name of the variable, port, or flag for the data value being returned.
CRBasic dataloggers support variable arrays (dimensioned variables). CSI
OPC Server supports only single-dimensioned variables, which take the
format:
CSIOPCServer.device_name.table_name.field_name(array_element)
Where field_name is the name of the dimensioned array and array_element is
the specific variable in the dimensioned array for the value being returned. As
an example, the variable array created by “Public Temp(4)” in a CR1000
program for a datalogger named WeatherCR1000 would have the data tags:
CSIOPCServer.WeatherCR1000.Public.Temp(1)
CSIOPCServer.WeatherCR1000.Public.Temp(2)
CSIOPCServer.WeatherCR1000.Public.Temp(3)
CSIOPCServer.WeatherCR1000.Public.Temp(4)
Multi-dimensioned arrays are only supported if the elements of the arrays are
given an alias. For example, you could use the following instructions in the
CR1000 program:
Public Temp(2,3)
Alias Temp(1,1) = TC1
Alias Temp(2,1) = TC2
Alias Temp(1,2) = TC3
Alias Temp(2,2) = TC4
Alias Temp(1,3) = TC5
Alias Temp(2,3) = TC6
And CSI OPC Server would show tags as TC1, TC2, TC3, etc.
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