If required, you can include multiple Traces on an ad hoc Trend. With a multiple trace Trend, each Trace has a different source. This is useful for comparing the data of several points or master station accumulators.
When multiple traces are supported, the TrendSpec definition typically has this basic structure:
TREND
(
TRACE(<Data Mode>,<Y-axis1 Name>,SOURCE (<Source1 Name>)),
TRACE(<Data Mode>,<Y-axis2 Name>,SOURCE (<Source2 Name>)),...,
TRACE(<Data Mode>,<Y-axisn Name>,SOURCE (<Sourcen Name>)),
XAXIS(<X-axis Mode>),YAXIS(<Y-axis1 Name>), YAXIS(<Y-axis2 Name>),...,
YAXIS(<Y-axisn Name>))
)
If the TrendSpec definition is to include Optional Values in addition to the Mandatory Values shown above, the definition typically has this structure:
TREND
(
TRACE(<Data Mode>,<Y-axis1 Name>,
SOURCE (<Source1 Name>,<SOURCE1 Optional Values>),
<TRACE1 Optional Values>),
TRACE(<Data Mode>,<Y-axis2 Name>,
SOURCE (<Source2 Name>,<SOURCE2 Optional Values>),
<TRACE2 Optional Values>),...,
TRACE(<Data Mode>,<Y-axisn Name>,
SOURCE (<Sourcen Name>,<SOURCEn Optional Values>),
<TRACEn Optional Values>),
XAXIS(<X-axis Mode>,<XAXIS Optional Values>),
YAXIS(<Y-axis1 Name>,<YAXIS1 Optional Values>),
YAXIS(<Y-axis2 Name>,<YAXIS2 Optional Values>),...,
YAXIS(<Y-axisn Name>,<YAXISn Optional Values>),<TREND Optional Values>
)
You will probably want to include optional values, for example, to specify a different color for each trace and corresponding Y-Axis, to reposition a Y-Axis, or to set some Y-Axes so that they are not visible on the Trend. For an example that demonstrates this, see Use TrendSpec to Define a Multiple Trace Ad Hoc Trend.
In some situations, multiple TRACE sections can be assigned the same YAXIS section. You can use such a structure to avoid including multiple YAXIS sections that would contain identical configuration, apart from the <Y-axis Name>. For an example that demonstrates this, see Use a ‘Standard’ Ad hoc Trend as the Basis for a ‘Custom’ TrendSpec Definition.