Материал: m083700e

AS-interface Master Module

750-655

The maximum process image of the AS-interface master comprises 48 bytes. When using a CANopen coupler / controller, the maximum mailbox size is limited to six bytes.

Each PDO can hold 8 bytes of data.

The first PDO, which is assigned to an AS-interface master module, contains the status / control byte, one empty byte and up to six bytes of mailbox or process data. The subsequent PDOs contain AS-interface process data.

The following table shows the assignment of the process image size to the number of occupied PDOs when the mailbox is permanently superimposed (Mode 1).

Input and Output Process Image

Here, the n-th PDO represents the first PDO occupied by the AS-interface Master module. It contains the status / control byte, one empty byte and up to six bytes of mailbox data.

If the length of the permanently superimposed mailbox is 0 bytes, then the nth PDO only contains the status / control byte and one empty byte.

If the process image of the AS-interface Master module is 12 bytes or 20 bytes in size, the last PDO is not fully occupied. A further module then starts with the next PDO.

WAGO-I/O-SYSTEM 750

CANopen

72• Fieldbus Controller 750-837, /02x-000, 750-838, /02x-000 Process Image

Note

When the mailbox size is 6 bytes and 62 AS-interface slaves are connected, a process image size of 40 bytes is sufficient to transmit all process data. The module then occupies five PDOs.

The following assignment of the process image size to the number of occupied PDOs applies in the operating mode with suppressable mailbox (Mode 2).

Input and Output Process Image

The n-th PDO contains the status / control byte, one empty byte and six bytes of mailbox data when the mailbox is superimposed, or the first six bytes of process data. The subsequent PDOs contain the further process data.

Note

When the mailbox is superimposed, it is not possible to access the first six bytes of process data (flags and slave 1/1A to slave 11/11A).

If the process image of the AS-interface Master module is 12, 20, 40 or 48 bytes in size, the last PDO is not fully occupied. A further module then starts with the next PDO.

WAGO-I/O-SYSTEM 750

CANopen

These modules present themselves with 1x 12...48 bytes, so that the object 0x4200-0x4202 for Gateway Modules, Inputs and the object 0x4300-0x4302 for Gateway Modules, Outputs are used. Therefore for each module one Subindex is occupied, within the Subindex 1 containes the mailbox size, Subindex 2 the mailbox and Subindex 3 to 48 the process data.

3.1.4.2.6 System Modules

System Modules with Diagnostics

750-610, -611

The 750-610 and 750-611 Supply Modules provide 2 bits of diagnostics in the Input Process Image for monitoring of the internal power supply.

Input Process Image

For the digital inputs the object 0x6000 (also 0x2000 possible) is used.

WAGO-I/O-SYSTEM 750

CANopen

74• Fieldbus Controller 750-837, /02x-000, 750-838, /02x-000 Data Exchange

3.1.5 Data Exchange

With CANopen, the transmission of data is made using communication objects.

Each communication object consists of a CAN telegram with 8 byte data and a unique COB-ID (Communication Object Identifier) in the network.

The transmission of data, the triggering of events, the signalling of error states etc. is made using communication objects.

Parameters for the communication objects as well as parameters and data of the CANopen subscribers are filled in an object directory.

3.1.5.1Communication objects

•The fieldbus controllers 750-837, /020-000, /021-000 and 750-838, /020-000, /021-000 supports the following communication objects:

•32 Tx-PDOs,

for process data exchange of fieldbus node input data

•32 Rx-PDOs,

for process data exchange of fieldbus node output data

•Server SDOs,

for exchange of configuration data and for information on the state of the node

•16 Client SDOs,

for the request for the configuration data of the own node or of 16 other fieldbus nodes (master function)

•Synchronization Object (SYNC), for network synchronization

•Emergency Objekt (EMCY)

•Network Management Objects

-Module Control Protocols

-Error Control Protocols

-Bootup Protocol

WAGO-I/O-SYSTEM 750

CANopen

3.1.5.2 Communication interfaces

For a data exchange, the CANopen fieldbus controller is equipped with three interfaces:

•the interface to fieldbus (-master),

•the PLC functionality of the PFC (CPU) and

•the interface to the bus modules

Data exchange takes place between the fieldbus master and the bus modules, between the PLC functionality of the PFC (CPU) and the bus modules as well as between the fieldbus master and the PLC functionality of the PFC (CPU).

3.1.5.3 Memory areas

The controller uses a memory space of 256 words (word 0 ... 255) for the physical input and output data.

The controller is assigned an additional memory space for mapping the PFC variables defined according to IEC 61131-3. This extended memory space (word 256 ... 511 each) is used to map the PFC variables behind the physical process image.

The division of the memory spaces and the access of the PLC functionality (CPU) to the process data is identical with all WAGO fieldbus controllers. Access is via an application related IEC 61131-3 program and independent on the fieldbus system.

Access from the fieldbus side is fieldbus specific.

WAGO-I/O-SYSTEM 750

CANopen