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6.6
Filtering commands
(a)
Filter band – ‘flb’
This command is used to set the point at which the adaptive filtering kicks in. It takes one
parameter which is the percentage of full scale of the input. Valid values are between
0.01% and 1.00%. Additionally the parameter can be OFF which will mean the filtering will
never kick in, or ON which means the filtering is always used. Note that if the filter size is
set to greater than 5 seconds, the filter band command will return a Bad Command
acknowledgement because the filter is always on in this situation and it therefore makes no
sense to attempt to change the band setting. For more information on this see the
Principles section (7.6).
To retrieve the current filter band, use the query ‘flb?’. The returned data is:
FILTERING BAND:
<band>
%
(b)
Filter size – ‘fls’
Use this command to set the size of the adaptive filtering buffer. The one parameter this
command takes is the buffer size in seconds, between 0 and 6 seconds. (0 can be used to
effectively turn the adaptive filtering off).
To retrieve the current filter size, use the query ‘fls?’. The returned data is:
FILTERING SIZE:
<x>
sec
… where <x> = number of seconds of filtering
[Note if current size is 0 then returned data is:
FILTERING SIZE: 0 (NO FILTER)
]
6.7
Relay control commands
(a)
Relay trip point – ‘rlt’
This command sets the point at which the relay switches from one state to the other. When
the source data is below this point then the relay is closed, so therefore when the source
data rises above this point then the relay is open. The command takes two parameters –
the first is the relay whose trip point is to be set (1-2) and the second is the trip point in
engineering units, as configured with the Input Channel range command (see 6.5(b)). Note
that the first parameter is always required even if the second relay has not been factory
fitted.
The current trip point values can be retrieved using the query ‘rlt?’. The returned data is
one line for each relay, as follows:
RELAY
<x>
TRIP POINT:
<trip point, in engineering units >
… where ...
<x> = the relay number
