Материал: m083700e

According to the IEC 61131-3 programming, data processing occurs locally in the PFC. The link results created in this manner can be put out directly to the actuators or transmitted to the higher ranking control system via the bus.

The process data exchange is made via PDOs and SDOs. The controller supports 32 Tx and 32 Rx PDOs, as well as 2 server and 16 client SDOs for sending process data via the CANopen fieldbus.

The programmer has access to all fieldbus and I/O data.

In the initialization phase the fieldbus controller determines the physical structure of the node and creates a process image from this with all inputs and outputs. This could involve a mixed arrangement of analog (word by word data exchange) and digital (byte by byte data exchange) modules.

The local process image is subdivided into an input and output data area.

The data of the analog modules are mapped into the PDOs according to the order of their position downstream of the bus coupler. The bits of the digital modules are compiled to form bytes and also mapped into PDOs. Should the number of digital I/Os exceed 8 bits, the coupler automatically starts another byte.

The entries in the object directory can be mapped to the 32 RxPDOs and 32 TxPDOs as required. The entire input and output data area can be transmitted with the SDOs.

“Spacer modules” can be set using the software.

WAGO-I/O-SYSTEM 750

CANopen

42• Fieldbus Controller 750-837, /02x-000, 750-838, /02x-000 Hardware

3.1.2 Hardware

3.1.2.1 View

The fieldbus controller is comprised of:

•Device supply with an internal system supply module as well as power jumper contacts for the field supply via assembled I/O modules

•Fieldbus interface with the bus connection

•DIP switch for baud rate and node ID

•Display elements (LEDs) for status display of the operation, the bus communication, the operating voltages as well as for fault messages and diagnosis

•Configuration and programming interface and operating mode switch

•Electronics for communication with the I/O modules (internal bus) and the fieldbus interface

WAGO-I/O-SYSTEM 750

CANopen

3.1.2.3 Device supply

The supply is via fed in terminal blocks with CAGE CLAMP® connection.

Device supply is intended for system supply and field side supply.

The integrated internal system supply module generates the necessary voltage to supply the electronics and the connected I/O modules.

The fieldbus interface is supplied with electrically isolated voltage from the internal system supply module.

WAGO-I/O-SYSTEM 750

CANopen

44• Fieldbus Controller 750-837, /02x-000, 750-838, /02x-000 Hardware

3.1.2.4 Fieldbus connection

The connection point is lowered in such a way that after a connector is inserted, installation in an 80 mm high switchbox is possible.

The electrical isolation between the fieldbus system and the electronics is made via the DC/DC converter and the optocoupler in the fieldbus.

For both fieldbus controller the shield on the CANopen communication cable must be connected to drain. The shield is connected via a 1 MΩ resistor to ground (earth) (rail carrier contact). A connection of low impedance between shield and ground (earth) can only be made externally (for example by a supply terminal block). It is recommended to have a central ground (earth) contact for the whole CANbus shield.

3.1.2.4.1 MCS (750-837, /020-000, /021-000)

3.1.2.4.2 D-SUB (750-838, /020-000, /021-000)

WAGO-I/O-SYSTEM 750

CANopen

3.1.2.5 Display elements

The operating condition of the fieldbus controller or node is displayed via light diodes (LED).

More Information

The evaluation of the displayed LED signals is described in Chapter 3.1.8 "LED Display"

WAGO-I/O-SYSTEM 750

CANopen