Data Acquisition; Trend; Connections And Application; Views - Siemens RMB795B Basic Documentation

Connections
Application
Examples
Contents
Change between views
Siemens
Building Technologies
15

Data acquisition

15.1

Trend

15.1.1 Connections and application

The following illustration shows the function block connections as shown on the
configuration sheet:
The Trend function block is used for time-related recording of measured values. It
provides 4 independent trend channels.
A trend channel can record one measured value.
Two trend channels can be displayed per Trend view: Primary channel plus extra
channel as a reference.
It is possible to record signals from local inputs of the central control unit RMB795B
as well as room temperatures and outside temperature via bus.

15.1.2 Views

The following illustration shows a 24-hour view on the operator unit with primary
trend curve and reference curve for an extra channel:
The current 24-hour views (8 minutes, 8 hours, 24 hours) show the date and the
current value of the primary trend curve at the top.
The primary trend curve is shown as a solid line, the reference curve as a dotted
line.
The Y-axis label refers to the settings of the primary channel. If the Y-axes of the
two channels do not match, a warning symbol appears below the axis.
Navigation between the 4 different views is made easy with the OK knob of the
operator unit:
• 8-minute view: Sampling every 5 seconds, last 8 minutes.
• 8-hour view:
Sampling every 5 minutes, last 8 hours.
• 24-hour view: Sampling every 15 minutes, current day.
• Rolling over the last 6 days: Sampling every 15 minutes, last 6 days.
Comment: The 24-hour view shows the last 6 days.
Central control unit RMB795B
Data acquisition
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CE1P3122en
18.01.2012