RingBufferFirstTime (FPScript)

21.09.2021

Provides the date and time of the first (oldest) available measurement value from a HistoryBase ring buffer.

Syntax

RingBufferFirstTime(HistoryBaseFile [ , Machine = "" ])

 

The syntax of the RingBufferFirstTime function consists of the following parts:

Part

Description

HistoryBaseFile

Path to the ring buffer file to be read.

Permitted data structures are scalar value. Supported data types are string (file name).

Machine

Name of the computer on the network on which the HistoryBase ring buffer server is running. This argument can also be an empty text. In this case, the HistoryBase instance of the ring buffer will be searched or, if necessary, instantiated on the executing machine.

Permitted data structures are scalar value. Supported data types are string.

If this argument is omitted, it will be set to the default value "".

Remarks

The result always has the data structure scalar value.

The Weisang HistoryBase ring buffer version 2.4 or higher has to be installed on the executing system and, if applicable, on the system specified by Machine. If data is currently being written to the ring buffer, the function uses a security buffer to ensure that the returned time value can be safely used as a starting time for a following execution of the RingBufferRead and RingBufferReadTime functions.

If an argument is a list, then the first element in the list is taken. If this is also a list, then the process is repeated.

Available in

FlexPro View, Basic, Professional, Developer Suite

Examples

RingBufferFirstTime("C:\RingBuffer.rbf", "RemoteMachine")


See Also

RingBufferRead Function

RingBufferReadTime Function

RingBufferLastTime Function

IsTimeInRingBuffer Function

Share article or send as email:

You might be interested in these articles