GE Industrial Solutions Control System Toolbox For Configuring the Trend Recorder - Manual (Page 9)

GEH-6408A Trend Recorder Chapter 1 Overview
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Chapter 1 Overview
Introduction
This document can apply to
various controllers or drives,
therefore the contents of the
dialog boxes can vary
according to your product. This chapter describes the Trend Recorder, which monitors and graphs signal values
from controllers or drives and graphs data collection analysis (.dca) files. Data can
also be saved and exported for other applications, such as spreadsheets.
Data Collection
The Trend Recorder uses three methods to collect data: real-time, block-collected,
and reading .dca files.
Real-time
Real-time data is collected by the toolbox. Real-time mode is for low to medium
data collection rates. Signals can be trended from controllers and drives. When you
are real-time trending data from a controller, both internal signals in the device and
any external signal on a drive local area network (DLAN+) that the device is
attached to can be trended. All the signals are sampled at the same time by a task
running in the device. The sample set is then transmitted over the network to the
toolbox. You can set the sampling rate when you are configuring the trend. The
minimum interval between samples is 32 ms.
Real-time trending of internal data from a controller requires that the controller file
be loaded in the toolbox while the trend is being set up. DLAN+ signals can be
added to the trend without having the device file open in the toolbox; however, the
toolbox must have access to the System Database (SDB). Once the trend is set up,
data can be collected and displayed from a controller without the controller being
loaded in toolbox.
It is not necessary to have the
device file loaded while
replaying previously collected
data. Only internal signals can be trended from an AcDcEx. Signals are sampled one at a
time, sequentially. The sample interval between signals is an average 22 ms. The
interval between samples of the same signal is the number of signals multiplied by
the interval between samples. When real-time trending signals from a drive, you
must have the device file open in the toolbox while the trend is set up and also when
data is collected.