Allen-Bradley 1734-OB2, Руководство пользователя, Страница: 104 / 221

Rockwell Automation Publication 1734-UM001E-EN-P - July 2013
106 POINT I/O Module Data
Alarm Disable
This function disables all channel alarms and faults so they are not reported in
the channel status field. The channel indicator stays solid green, alarms are
ignored. The default state is Alarms Enabled. Each channel can be configured
individually.
Calibration Status
This status bit is set when the channel is in Calibration mode. At Begin
Calibration, the module is put into Calibration mode. This bit is reset when the
Accept Low Calibration, or Accept High Calibration, commands are sent. This is
not
the Bad Calibration Status bit, which is set if the module is
not
calibrated.
Digital Filter
A digital filter is available on the input modules. You set a time constant that is
used in the equation:
Yn = Yn-1 + (dt / (dt + T
A
) * (Xn-Yn-1)
Where: Yn = new data
Yn-1 = old data.
dt = Channel Update Rate in milliseconds
T
A
= digital filter time constant
Xn = present unfiltered data
T
A
can be an integer from 0...10,000 ms. If set to 0, the filter is disabled
The default setting is disabled. This is done by setting the time constant (TA) to
zero. Each channel can be configured individually for time constant but update
rate (dt) is done on a per module basis.
Update Rate
The update rate determines how often a channel is scanned. The maximum rate is
determined by the notch filter setting. The minimum update rate is 10,000 ms.
•
120 ms maximum update rate - 50 Hz
•
100 ms update rate - 60 Hz
•
24 ms update rate - 250 Hz
•
12 ms update rate - 500 Hz
Notch Filter
Select a notch filter. The notch filter is for both inputs. Valid settings are the
following:
•
50 Hz - 120 ms maximum update rate