Rockwell Automation T7832 ICS Regent+Plus Historian Packages for Winterpret - Manual (Page 4)

Historian Package for W INTERPRET (T7832)
4
Industrial Control Services
Process Historian Function Blocks
Process historian function blocks let the Regent record and
time stamp the values of selected process variables. In a
typical application, the process historian begins recording
when a start signal occurs. At periodic intervals, it records
time stamps and values into a historical buffer in the Regent.
When this historical buffer is full, recording continues by
overwriting the oldest time stamps and values in the list.
Because the recording mode of the process historian is
controlled by a start bit within the Regent, process historian
can be used to capture selected process variable information
during critical process control, alarm or interlock conditions.
This historical recording can be performed at high speed
(maximum once per scan) within the Regent. The data can be
retrieved by monitoring the process historian function block
using W
INTERPRET . When retrieved from the Regent the
historical data is saved to a Log file which can be viewed,
printed, or analyzed using database, spreadsheet or other
third party analysis software.
Process historian function blocks can be included in programs
containing other types of function blocks (such as ladder logic,
continuous control, floating point math, analog scaling, ASCII
output, and sequence of events).
Users of the process historian function blocks discover
operating details of their processes that they had never before
observed or recorded. Their analysis of this data leads to more
accurate definition of the process safety interlocks which can
result in fewer nuisance trips.
Monitoring and Collecting Historical Data
From the Regent
The Regent is capable of buffering historical data in its
memory without requiring any external communications
equipment connected (like a PC running W
INTERPRET ). This
function stores the information in the allocated historian
buffers for each function block. To retrieve the information
from the internal memory buffers, you can use W
INTERPRET to
monitor and collect the historical buffers and save the
information as Log files in ASCII text file form on the PC.