32
Operating Instructions
●
Number_Of_APDU_Retries
(73)
: This is the number of retries for packets. The WattNode
meter does not send packets expecting a response, so this read-only value is zero.
●
Device_Address_Binding
(30)
: The WattNode does not use
Device_Address_Binding
and
always returns an empty list if this is requested.
●
Max_Master
(64)
: This is the highest supported address for master nodes. For the WattNode
meter, this is set to 127 and cannot be changed.
●
Max_Info_Frames
(63)
: This is the maximum number of information frames the node may
send before passing the token. Since the WattNode only responds to incoming requests, this
value is fixed at 1.
●
Database_Revision
(155)
: This integer count starts at one and increases by one each time
the device object identifier (device ID) is changed. This is preserved across power failures.
●
Last_Restart_Reason
(196)
: This is the reason for the most recent device restart:
UNKNOWN (0):
Unexpected or unknown restart reason
COLDSTART (1):
Power-on or ReinitializeDevice=COLDSTART request
WARMSTART (2):
Firmware upgrade or ReinitializeDevice=WARMSTART request
DETECTED_POWER_LOST (3):
The device detected that incoming power was lost
HARDWARE_WATCHDOG (5):
The watchdog timer reset the device
SOFTWARE_WATCHDOG (6):
A software error caused a device reset”
Analog Input Objects - Measurements
For all the analog input objects the following properties are supported:
●
Present_Value
(85)
: This reports the measured value as a floating point number.
●
Object_Identifier
(75)
: A combination of the
Object_Type
and
Object_Number
.
●
Object_Name
(77)
: A string name for this object, such as
EnergySum
.
●
Object_Type
(79)
: Reports ANALOG_INPUT (0) for all analog input objects.
●
Units
(117)
: The BACnet engineering units for this measurement.
●
Status_Flags
(111)
: This required property reports the following four flags, each of which may
be TRUE (1) or FALSE (0).
○
IN_ALARM (Bit 0)
: FALSE if
Reliability
indicates “No fault detected”; otherwise TRUE
indicating some reliability problem.
○
FAULT (Bit 1)
: FALSE if
Reliability
indicates “No fault detected”; otherwise TRUE indicat-
ing some reliability problem.
○
OVERRIDDEN (Bit 2)
: Always reports FALSE because the WattNode meter does not
support analog input overrides.
○
OUT_OF_SERVICE (Bit 3)
: Always reports FALSE, same as
Out_Of_Service
property.
●
Event_State
(36)
: This required property indicates either of the following:
○
NORMAL (0)
: Reported if the
Reliability
property indicates “No fault detected”.
○
FAULT (1)
: Reported if the
Reliability
property indicate a problem.
●
Out_Of_Service
(81)
: This is read-only and will always be FALSE (0).
●
Reliability
(103)
: This indicates if the associated measurement is reliable or not. The
WattNode will return any of the following values:
RELIABILITY_NO_FAULT_DETECTED (0):
No fault detected
RELIABILITY_NO_SENSOR (1):
Error communicating with the measurement sensor
RELIABILITY_OVER_RANGE (2):
, The measurement was above the maximum valid value
RELIABILITY_UNDER_RANGE (3):
The measurement was below the minimum valid value
RELIABILITY_UNRELIABLE_OTHER (7):
Indicates a bad firmware checksum
●
Update_Interval
(118)
: This reports (in hundredths of a second) the time between updates to
this object. Most WattNode measurements update once a second. Demand objects update at
the end of each demand interval or subinterval.