41
Command:
#01fa05[cr]
To confirm the change, re-send the initial Read Command.
FB (Filter Band)
The filter band determines whether or not filtering is taking
place and what percentage of the pressure span is being
filtered (by the amount set in FA). Filtering is disabled if a
pressure transient exceeds the value set for FB. This feature
ensures that filtering will not occur if the transducer sees sud-
den “spikes” or rapid rate of change in the pressure source.
To read the current value of FB for a transducer with address
01, send the following read command:
#01FB[cr]
The unit will respond with the following display:
FB=0059 (or whatever the current value is)
The minimum value is 0002 and maximum is 9999 which
represents an incremental value of ±0.001% of full scale.
Therefore the maximum bandwidth is ±10% of full scale.
To change the value of FB, a four character value must be
included in the FB Write Command. The following table pro-
vides an abbreviated listing of possible values and their effect
on the bandwidth.
Filter Band Values
FB
Effect as %
Values
of Full Scale
0001
0.000% FS
0002
0.002% FS
0050
0.05% FS
0250
.25% FS
1000
1.0% FS
5000
5.0% FS
9999
9.999% FS
To change the current value of FB from its current value of
0250 (±0.25%) in a transducer with address 01, send the fol-
lowing Write Command:
#01fb0250[cr]
To confirm the change, re-send the initial Read Command
NOTE: Due to resolution limitations in the math package it is
necessary to add one count more to the FB value to obtain
the expected % of full scale counts as anticipated, in some
cases.
Example: #01fb0030 should set the FB to .03% of 50,000,
set in terms of counts, or 15 counts. In actuality, due to
resolution issues, the count is only set to 14. To get the full
15 counts, the command needs to have one count added
(.001%):
#01fb0031
This will set the full 15 counts for FB.
As an added feature, the actual % of 50,000, set in terms of
counts, can be read from the EEProm in the DXD by using
the ER command at locations 158 (upper byte) and 159
(lower byte):
To read the FB in terms of counts from a transducer with
address 01, with a FB value set to 003, send the following
Read Command:
#01ER159[cr]
The response will be:
015