TSI Instruments FHC50, Руководство по эксплуатации и обслуживанию

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N2 Communications Description of Variables 77
N2 Communications
Description of Variables
Description of Variables
Variable Description
NPT - Network
Point Type
Variables are defined as analog inputs, binary inputs, and analog outputs.
Analog inputs are current control parameters and items that the controller is
measuring. Binary inputs represent controller states. Analog outputs are the
programmable set points for the Fume Hood Controller. These set points can
be changed through the keypad or by over-writing the current set point.
NPA - Network Point
Address
Address of the desired point.
Change of Status
(COS) - Face Velocity
Analog Input The FHC50 has the ability to change control set points locally. The alarm set
points need to be based on the controllers control set point (AI #2). The unit can
be changed from Normal Mode to Setback Mode. For example the set point
could go from 100 ft/min to 60 ft/min when the Setback key is pressed. If the
COS alarm set points are not changed to accommodate you could get low
alarm or low warning messages when the unit is working correctly. If these
alarm points are set outside of the setback and main velocity set point values,
incorrect alarm messages can be prevented.
Override Analog
Input Command The Damper Position Analog Input value can be set using the override
command. This value will be reset to the correct item when the Override is
released. There is not a time-out on the override command.
Other Analog Input values cannot be Overridden.
Override Binary
Input Command Overriding a 1 to the Setback or Emergency binary inputs enables the
respective mode. To return the controller to normal mode from setback mode,
press the Setback key on the controller, toggle the setback contact input, or
release the override. To release controller from emergency state, override a 0
to the Emergency input, toggle the emergency contact input, or press either
the emergency or reset key. Releasing the override will return the controller to
the state it was in previous to the emergency, either Normal or Setback.
The alarm, data error, and sensor error variables can be overridden, but this
will not affect the controller. Overriding the low alarm variable will result in a
change of status, but will not put the controller into low alarm mode. The local
alarm modes can only be controlled locally. Only override these variables for
diagnostic purposes, and release them for normal operation.
Binary Inputs, Sensor
Error and Data Error Sensor Error and Data Error binary inputs are used to indicate if something
has gone wrong with the controller. The Sensor Error is set when the sensor
on the controller has a malfunction. This indicates that service should be done
on the controller. Data Error indicates when some of the data stored on the
device has been corrupted. The calibration and set point values should be
checked on the controller.
Override Analog
Output Command The analog output variables can be overridden to change their values. The
overridden value will be checked for validity. If invalid, the override command
will be ignored, and the value will not change. The override flag will not be set
when the value is ignored. The override command will be cleared when the
variable is reset in the menus. The variable will not reset with the release
command.