Measurement Computing eZ-Record rev.2.1 - Manual (Page 47)

47
January 2001 eZ-Record Manual
U
SING
B
ANKS AND
F
UNCTION
F
ILES
A Bank is defined as a group of signals that are selected for simultaneous
measurement, together with all the associated transducer definitions and channel
assignment information. He concept of “banks” is helpful with a modal test where
the number of transducers on the test article exceeds the number of input
channels on your analyzer.
You can have the analyzer increment your banks automatically after each
measurement, or you can manually increment the banks. The Skip Factor is
typically the number of measurement points in a bank.
Use the Bank Up/Bank Dn button in the Main window to increment or
decrement your banks. Press the HOME key to switch this button between Bank
Up and Bank Down. The Bank control options are set up in the Channel Setup
window. Bank Up increments the Bank by the Skip Factor. Bank Dn decrements
the Bank by the Skip Factor. The number of channels associated with a bank are
based on the Response Channel and the Skip Factor.
H
INTS FOR
S
ETTING UP
B
ANKS AND
S
KIP
F
ACTORS
Visualize a test object with 27 transducer locations in 3 rows of 9. You have 1
reference, and 27 responses. Using all 8 channels you can build channel pairs
with channel 1 as the reference, and 2 through 8 as the responses. Your 7 channel
pair relationships would be 2,1 3,1 4,1 5,1 6,1 7,1 and 8,1
In the Channel Pairs window specify channel 1 as a reference channel; then
click the Build Pairs Button to create the channel pairs listed above.
In the Channel Setup window place an “X” in the Skip Factor Response
Channel check box. This tells the analyzer to count the number of active
response channels and use that number as the skip factor. Also place an “X” in
the Auto Bank Increment check box so that each time we click the Export button,
the bank will automatically increment for us.
Example: The skip factor is 7 in this example.
Bank Reference channel/location Response channel/location
1 1/1 2/2, 3/3, 4/4/, 5/5, 6/6, 7/7, 8/8
2 1/1 2/9, 3/10, 4/11, 5/12, 6/13, 7/14, 8/15
3 1/1 2/16, 3/17, 4/18, 5/19. 6/20, 7/21, 8/22
4 1/1 2/23, 3/24, 4/25, 5/26, 6/27
In the Export Setup window define the path to the directory where you want
files saved. Select only FRF as the function to save. Now each time an
acquisition is perform, an FRF is acquired into memory for each channel pair at the
defined location.
Before starting data acquisition, use the HOME key to toggle the Bank Up/
Bank Dn direction to Bank Up. This tells the analyzer to automatically increment
the bank each time the Export button is clicked.
After each acquisition, click the Export button to create an FRF file for each
channel pair. Each file name identifies the reference location and orientation, and
the response location and orientation, using the function abbreviation [in this
case FRF] as the file extension.