B&R PVI Interface (Bernecker & Rainer Process Visualisation Interface)

Protocol description
Communication line configuration
Station configuration
I/O tag configuration
Literature
Changes and modifications
Document revisions

Protocol description

The B&R PVI Interface protocol is used to communicate with the B&R PLC using the PVI interface from Bernecker & Rainer. The following features are supported:

• reading and writing (input and output I/O tags),
• reading and writing simple types (i8, i16, i32, i64, u8, u16, u32, u64, boolean, string, wstring, time, dt, date, tod),
• working with individual items (which are of simple types) of structured variables,
• reading arrays into structured I/O tags with a configured  Destination column of the structure.

Working with the "data" data type is not yet supported.

Communication was tested with both virtual and physical B&R PLC with PVI versions:

• Automation Net PVI V4.0
• Automation Net PVI V4.2
• Automation Net PVI V4.3
• Automation Net PVI V4.7

Hierarchy of PVI objects

B&R PVI defines the following object hierarchy for the INA2000 line, which is used to communicate with the B&R SG3, SGC, and SG4 control units via the INA2000 (Industrial Network Architecture) protocol.

Line and Device objects are configured in the protocol parameters of the D2000 communication line.

Station, CPU, Module, and Task objects are configured in the protocol parameters of the D2000 communication station.

Variable objects are configured as D2000 I/O tags.

Communication line configuration

• Communication line category: API.

Line protocol parameters

The following global line protocol parameters can be configured for the "B&R PVI Interface" protocol:

Station configuration

• The communication station corresponds to the device with which the KOM process communicates. At the station protocol parameter level, objects of Station, CPU, Module, and Task types are specified.
• Communication protocol "B&R PVI Interface".

Station protocol parameters

Configuration dialog box - tab Parameter.
They influence some optional parameters of the protocol. The following station protocol parameters can be set:

Table 1

I/O tag configuration

Possible types of I/O tag values: Ai, Ao, Di, Do, Ci, Co, TiR, ToR, TiA, ToA, TxtI, TxtO.

I/O tag address:

The I/O tag corresponds to an object of Variable type.

The address of the /O tag is in the form Parameter1=value1 [Parameter2=value2] ...

Mandatory parameters are CD=variable_name VT=value_type.
Parameter VL=element_length is mandatory for strings and wide strings (VT=string and VT=wstring).
Parameter VN=number_of_elements is mandatory for array values.
Note: the I/O tag is ignored if its address starts with %IGNORE

According to the PVI documentation, the following parameters are supported:

Examples of configuration:

• CD=gByte VT=u8 RF=10 - 1-byte unsigned variable gByte, 10 ms refresh rate
• CD=gMyInt VT=i16 HY=5 - 2-byte signed variable gMyInt, with hysteresis 5 (a change less than 5 will not be reported)
• CD=gDate RF=250 AT=rw VT=date - variable gDate of date type, access for reading and writing, 250 ms refresh rate
• CD=gmArrInt VT=i16 VN=6 - variable gmArrInt is array of 16-bit signed integers, first 6 array items will be read
  Note: For reading of more than one array item to make sense, the Destination column must be configured for the I-O tag.
  Note: Variable with "VN=number_of_items" parameter is for reading only. If writing is required, each array item must be configured as a separate I-O tag (see next example).
  CD=gmArrInt[0] VT=i16 - the item zero of an array of 16-bit signed integers gmArrInt (arrays in B&R PLC by default start with a zero entry similar to C)
• CD=string_arr RF=250 AT=rw VT=string VL=6 VN=5 - variable string_arr is an array of 6-byte strings, first 5 array items will be read, 250 ms refresh rate
  Note: If a string has 6 bytes, it will only fit 5 characters (the last byte is a trailing zero).
• CD=wstring_arr VT=wstring VL=42 VN=4 - variable wstring_arr is an array of 6-byte wide strings (2-bytes per character) reťazcov, first 4 array items will be read
  Note: If a wstring has 42 bytes, it will only fit 20 2-byte characters (the last 2 bytes is a trailing zero).
• CD=Controll.cmd.SetPoint VT=f32 VL=4 VN=1 - item SetPoint of substructure cmd of structured variable Controll is a 32-bit floating-point number

Browse

For the I/O tags,  it is possible to find a list of objects of Variable type and their data types and other details, as long as the KOM process is running and communication with the station is established.
Clicking the Browse button opens the B&R PVI Item Browser window and displays a list of objects.

Figure - B&R PVI Item Browser window

The window displays the following information:

Task: the name of the task (if it is a local variable), or an empty string (if it is a global variable). By default, only local variables belonging to the task specified as the Task object definition parameter are read. If the Browse task parameter is enabled, the local variables of all tasks are read.

Variable: variable name in B&R PLC (value of the CD parameter )

Parameters: other parameters of the variable (see the configuration of the I/O tag)

Point: the name of the I/O tag that is configured for this object

Filtering in the list of objects: the browse window allows you to filter by the values ​​displayed in each column. The values don't have to be entered completely. The notation *FILTERED EXPRESSION* is sufficient, where the asterisks represent any text before the start and end of the expression (e.g., *put* covers both input or output).

The total number of objects: the total number of objects in all object groups is displayed at the bottom left of the window.

Meaning of individual options and buttons:

Copy all to clipboard

Copies all displayed objects and details to the Windows Clipboard.

Refresh

The Refresh button can be used to force the object list to be re-read from the device. By default, the KOM process reads the list of objects and their data types only for the first request and stores it in memory. Depending on the number of objects and the speed of the device, this reading may take a longer time. It then sends this stored list to the CNF process(es), so that the next reading of the list in the DNP3 Item Browser window is fast.

Cancel

D2000 Cnf has the recycling of browser windows implemented. If the window is closed by the Cancel button or after selecting an object, it is actually only hidden and is available for browsing for another I/O tag within the same station, so that the list of objects being viewed is preserved. Clicking on the cross at the top right corner will cause the window to actually close.

In the case of structured variables, the window displays individual items that are of basic types. If the local variables of all tasks are browsed ( the Browse task parameter), the local variables not belonging to the task specified as the Task object definition parameter will be displayed in gray and cannot be selected. The following figure shows the items of structured variables as well as local variables of other tasks:

Literature

PviBase.chm PVI Base system - B&R documentation

Changes and modifications

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Document revisions

• Ver. 1.0 - April 1st, 2021 - a document created.