Bonfiglioli Vectron EM-SYS System Bus Networking and Virtual Link Configuration Guide

989=0 (Error): After receiving an emergency message, the master station also enters a fault state and reports fault code F21nn (nn is the hexadecimal node ID of the faulty slave station). Meanwhile, the warning bit Sysbus (0x2000) is set.

989=1 (No Error): The main station only displays a warning and does not trigger its own fault.

Chapter 3: SDO Channel - Cross Bus Parameter Access Mechanism

SDO (Service Data Object) channel is used for reading and writing parameter data, and is the core tool for remote configuration and diagnosis.

3.1 Dual channel design of SDO1 and SDO2

Each frequency converter provides two SDO channels (Chapter 4.7.1):

SDO1: Used for parameterized access from the master station (PLC/PC or master station frequency converter) to the slave station.

SDO2: Reserved for online parameter monitoring of visual debugging tools (such as VPlus).

The identifier of SDO1 follows CANopen's predefined connection set by default:

Rx-SDO1 (master station → slave station): 1536+Node-ID

Tx-SDO1 (slave → master): 1408+Node-ID

3.2 SDO Message Structure and Data Access

SDO adopts the Expedited SDO protocol (Chapter 4.10.1) to complete parameter transmission within one CAN frame. The core frame structure is as follows:

Control byte: 0x22 (download/write request) or 0x40 (upload/read request).

Index/Sub Index: Index=Parameter Number (PNU), Sub Index=Dataset (DS 1-4).

Data byte: 4 bytes, used to carry uint/int (valid for the lower 2 bytes) or long (valid for all 4 bytes) type data.

3.3 Cross bus parameter access (main station frequency converter as gateway)

When the EM-SYS module and the fieldbus module (such as CM-PDP, CM-232/485) are installed together in the same frequency converter, the frequency converter serves as the system bus master and can act as a protocol gateway (Chapter 4.10.2):

Through Profibus DP (PKW channel): Fill the system bus node ID into Byte 3 (Index byte) of the communication channel to read and write parameters to the node.

Through the VABus serial protocol, cross bus access is achieved by filling in the node ID (ASCII encoding) in the reserved byte of the telegram header (Byte 1 of Inquiry or Byte 2 of Select).

This mechanism allows the upper level PLC to access all nodes of the entire system bus network through the main station frequency converter without directly connecting to each frequency converter.

Chapter 4: PDO Channel and "Virtual Link" Mapping

The PDO (Process Data Object) channel is the core of the system bus for real-time data exchange. EM-SYS provides three sets of PDO channels (PDO1, PDO2, PDO3), each containing a transmit (TxPDO) and a receive (RxPDO) direction.

4.1 PDO identifier and communication mode

The default identifier follows the CANopen predefined connection set (Chapter 4.11.1):

TxPDO1：384 + Node-ID

RxPDO1：512 + Node-ID

TxPDO2：640 + Node-ID

RxPDO2：768 + Node-ID

TxPDO3：896 + Node-ID

RxPDO3：1024 + Node-ID

Each PDO channel can be configured for two working modes (Chapter 4.11.2):

Time controlled: TxPDO sends cyclically at fixed time intervals (such as TxPDO1 Time 931); After receiving the data, RxPDO immediately forwards it to the application.

SYNC controlled: TxPDO sends a unified SYNC synchronization message after receiving it; RxPDO forwards data to the application only after receiving SYNC. This mode is suitable for scenarios that require multi axis synchronous locking.

4.2 PDO timeout monitoring

To ensure communication reliability, PDO timeout monitoring can be enabled (Chapter 4.11.3):

SYNC Timeout 939: Monitor the arrival timeout of SYNC messages.

RxPDO1/2/3 Timeout 941/942/945: Monitor the data update timeout of each RxPDO channel.

Timeout will trigger faults: F2200 (SYNC timeout), F2201-F2203 (RxPDO timeout).

4.3 "Virtual Link" Mapping - Core Innovation Mechanism

Traditional CANopen uses Mapping Parameters to define the data content of PDO. EM-SYS adopts a more intuitive "Sources and Links" approach (Chapter 4.11.5).

Principle: The output data of each functional module is assigned a source number (Source No.). The input data for each functional module is specified by the source number connected through parameters. When data is transmitted across two frequency converters, a 'virtual link' is formed.

TxPDO data packaging (sender):

Each TxPDO contains 8 bytes and can flexibly package different types of data (Chapter 4.11.5.1):

4 Boolean variables (each occupying 2 bytes, actually using 1 bit) or 4 Word/Integer variables (each occupying 2 bytes) or 2 Long variables (each occupying 4 bytes), or mixed packaging.

The sender fills the required data source number into the specified byte position of TxPDO through parameters:

For example, TxPDO1 Word1 950=740 (place the control word source 740 into the 1st/2nd byte of TxPDO1).

For example, TxPDO1 Long1 954=62 (insert reference frequency source 62 into bytes 1-4 of TxPDO1).

RxPDO data unpacking (recipient):

The receiver's RxPDO maps the received 8-byte data to available source numbers (Section 4.11.5.2):

RxPDO1 byte 1/2 corresponds to source number 704 (Boolean) or 705 (Word).

RxPDO1 bytes 1-4 correspond to source number 708 (Long).

The receiver connects the RxPDO source number to the input of the target function through parameters: