Overview

A 'Cpu' represents a PLC in a network.

The 'Cpu' is the parent of a 'Task' or a (global) 'Variable' or a 'Module'.

Furthermore a 'Cpu' can be restarted (cold/warm) or be used to create a module on the PLC.

It is advisable to always use callback 'errorChanged' and check for status '0' before accessing an Object that is located on an Cpu e.g.

cpu = Cpu( device, 'myCpu', CD='/IP=10.43.50.244 /COMT=3000' )
    ...

def cpuErrorChanged( error : int):

    if error == 0:
        # do something useful
        ....
    else:
        # not yet connected or in error state
        ...

cpu.errorChanged = cpuErrorChanged

pviConnection.start()

ANSL

The ANSL CPU object is used to define the PLC within a network and to set the parameters of the ANSL communication connection.

Example:

from pvi import *

pviConnection = Connection() # start a Pvi connection
line = Line( pviConnection.root, 'LNANSL', CD='LNANSL')
device = Device( line, 'TCP', CD='/IF=TcpIp' )
cpu = Cpu( device, 'myCpu', CD='/IP=10.43.50.244 /COMT=3000' )

Connect to IP address 10.43.50.244 with a communication timeout of 3000 ms.

INA2000

The INA2000 CPU object is used to identify the PLC in a network or using (INA-) Routing and to set the connection parameters for communication.

Serial connected PLC

Example:

from pvi import *

pviConnection = Connection() # start a Pvi connection
line = Line( pviConnection.root, 'LNINA', CD='LNINA2')
device = Device( line, 'serial', CD='/IF=com1 /BD=57600 /PA=2' )
cpu = Cpu( device, 'myCpu', CD='/RT=400' )

Use COM1 to connect with 57600 Baud and Even Parity. Connect with a response timeout of 400 ms.

Ethernet UDP communication

Example 1:

from pvi import *

pviConnection = Connection() # start a Pvi connection
line = Line( pviConnection.root, 'LNINA', CD='LNINA2')
device = Device( line, 'TCP', CD='/IF=TcpIp /SA=113' )
cpu = Cpu( device, 'myPP65', CD='/DA=5 /RT=200' )

Connect to INA node 5 with a response timeout of 200 ms. Since we use broadcasting an IP address is not required.

Example 2:

from pvi import *

pviConnection = Connection() # start a Pvi connection
line = Line( pviConnection.root, 'LNINA', CD='LNINA2')
device = Device( line, 'TCP', CD='/IF=TcpIp /SA=113' )
cpu = Cpu( device, 'myPP65', CD='/DAIP=10.43.50.244 /RT=200' )

Connect to IP address 10.43.50.244 ignoring INA node numbers with a response timeout of 200 ms. Even INA node addressing is not used we need to define a unique 'source address' /SA for the device.

CAN station

from pvi import *

pviConnection = Connection() # start a Pvi connection
line = Line( pviConnection.root, 'LNINA', CD='LNINA2')
device = Device( line, 'inacan', CD='/IF=inacan3 /CNO=1 /SA=3' )
cpu = Cpu( device, 'myPP65', CD='/DA=13 /RT=600' )

Use channel '1' of local installed B&R CAN Adapter as configured via the "CAN devices" menu item in the Control Panel. Act as INA node 3. Connects to INA node 13 with a response timeout of 600 ms.

SNMP

Can be specified as an additional locical level but not required.

Reference: Cpu object