[MOV_CALC] Moving calculation

Function block MOV_CALC calculates preconfigured evaluation functions for a continuously updated internal data buffer.

MOV_CALC calculates preconfigured evaluation functions for a continuously updated internal data buffer.

MOV_CALC cyclically receives the input value [In] and stores it into an internal buffer. The size of the buffer is configured at input [BufSize] (maximum 60). The buffer contains values and timestamps for the time at which the values were sampled.

Storing the input data

Storing the input data into the buffer can be triggered in two ways:

Impulse (rising edge) at input [Trig]
Internal timer for the function block, configured via input [TiSmpl]

The value -1s for the input [TiSmpl] disables the internal timer. In such a case, new values in the buffer will be added only via input [Trig].

When the buffer is filled with data and a new value is requested to be stored, the oldest (earliest) sample in the buffer will be overwritten by the new value.

An input value is stored in the buffer only if it is valid. The validity of the input value is defined by the [Vldty] input.

Enable and disable the function

The input [EnFnct] disables the function block (outputs are set with default values).
Disabling the function block does not clear the internal buffer.

Reset

The [Reset] input is used to clear the internal buffer and to restart the calculations.

Calculation

The function block can calculate up to four evaluation functions for the data in the buffer.
These functions are configured at inputs [EvlFnct1] ... [EvlFnct4].
The results of the evaluation functions are provided at outputs [Val1] ... [Val4].

Buffer behavior

The function block provides an impulse at output [UpdInd] when a new value is added in the buffer.
[RecCnt] output provides the number of sampled values collected in the buffer.
Output [FstVal] provides the first (earliest) value in the buffer.
Output [FstTiStm] provides the time when the first (earliest) value in the buffer was received.
Output [LstVal] provides the last (most recent) value in the buffer.
Output [LstTiStm] provides the time when the last (most recent) value in the buffer was received.

Persistence of the buffer values

If [Pers] = 1 at start up, MOV_CALC reads the last saved buffer values from the associated BACnet object and uses them as initial buffer values. In the event of an error or if [Pers] = 0, the buffer is empty.
The properties 'Buffer size', 'Last value index', 'Record count', 'Values' and 'Time stamp for values' must be available on the associated BACnet object as extension property ('Extension by persistence' = 'Moving calculation').
Outputs [Dstb] and [ErrCode] indicate if an access error has occurred when the last saved values are read from the associated BACnet object.

Evaluation of more than 60 values

Input [SeqCnctIn] and output [SeqCnctOut] are used to link two MOV_CALC function blocks in sequence. Linking function blocks in sequence is used when a buffer with a size bigger than 60 is needed. When the buffer of the first function block is filled with values and a new value is received, the first (earliest) value in the buffer will be forwarded to the second function block before it is overwritten by the new value. When the input [SeqCnctIn] of the second function block is connected, then the values at its inputs [In], [Vldty], [Trig] and [TiSmpl] are ignored.

Pins

Input	Description	Data type	Default value Value range
EnFnct	Enable function Enables the function.	Boolean	1
EnFnct	0 - The function is disabled. 1 - The function is enabled.
In	Input Input signal	Real	0.0
Vldty	Validity Only valid input values are stored in the internal buffer.	Boolean	1
Vldty	0 - The input signal is not valid. 1 - The input signal is valid.
Trig	Trigger Trigger impulse for storing an input value in the buffer	Boolean	0
TiSmpl	Sampling time Time between the received input values	Time	15m 1m...1d
BufSize	Buffer size Size of the internal buffer	Integer	60 2...60
EvlFnct1...EvlFnct4	Evaluation function 1...Evaluation function 4 Evaluation function to be performed for the values in the buffer.	Integer	1: No function selected
EvlFnct1...EvlFnct4	1: No function selected 2: Sum 3: Average 4: Minimum 5: Maximum
Reset	Reset Reset internal buffer.	Boolean	0
Reset	0 - Do not reset 1 - Reset
Pers	Persistent	Boolean	0
Pers	0 - No 1 - Yes: the values are stored persistently.
SeqCnctIn	Sequence connection input Receives values from the previous function block in a sequence.	Structure	-
SeqCnctIn > Cnctd	Connected Indicates if a pin is connected.	Boolean	0
SeqCnctIn > RmvVal	Removed value Removed value from the buffer	Real	0.0
SeqCnctIn > RmvTiStm	Removed time stamp Removed time stamp from the buffer	DateAndTime	01.01.1990 00:00:00:000
SeqCnctIn > UpdInd	Update indication Indicates (rising edge) when a value is removed from the buffer.	Boolean	0
BaObjRef	BA-Object reference Link between function block and BACnet object.	Structure	---
BaObjRef > DeviceID	Device identifier [DeviceID] includes object type and object instance in one ID. Identifies the device object: local or remote. A local device object can also be identified by value 16#3FFFFF.	Double Word	16#3FFFFF
BaObjRef > ObjectID	Object identifier [ObjectID] includes object type and object instance in one ID. Identifies the object on a device.	Double Word	16#3FFFFF
BaObjRef > ItemID	Item identifier [ItemID] represents an index in a view node object that references the BACnet object. [ObjectID] and [ItemID] together define an indirect reference to the BACnet object. Value -1 indicates a direct interface.	Integer	-1

Output	Description	Data type	Default value Value range
Val1...Val4	Value 1...Value 4 Resulting value from the evaluation function selected in [EvlFnct1]...[EvlFnct4]	Real	0.0
UpdInd	Update indication Indicates (with an impulse) when a new value is added to the internal buffer.	Boolean	0
RecCnt	Record count Provides the number of sampled values collected in the buffer.	Integer	0
FstVal	First value Provides the first (earliest) value in the buffer.	Real	0.0
LstVal	Last value Provides the last (most recent) value in the buffer.	Real	0.0
FstTiStm	First time stamp Provides the time when the first (earliest) value in the buffer was sampled.	DateAndTime	01.01.1990 00:00:00:000
LstTiStm	Last time stamp Provides the time when the last (most recent) value in the buffer was sampled.	DateAndTime	01.01.1990 00:00:00:000
Dstb	Disturbed [Dstb] indicates whether the referenced BACnet object was accessed. [Dstb] = 0, if: BACnet object access = Access successful [Dstb] = 1, if: BACnet object access = Error during access	Boolean	0
SeqCnctOut	Sequence connection output Provides values for the next function block in a sequence.	Structure	-
SeqCnctOut > Cnctd	Connected Indicates if a pin is connected.	Boolean	0
SeqCnctOut > RmvVal	Removed value Removed value from the buffer	Real	0.0
SeqCnctOut > RmvTiStm	Removed time stamp Removed time stamp from the buffer	DateAndTime	01.01.1990 00:00:00:000
SeqCnctOut > UpdInd	Update indication Indicates (rising edge) when a value is removed from the buffer.	Boolean	0
ErrCode	Error code indication	Integer	0: No error
ErrCode	= 0 - No error > 0 - Error codes