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

For example, Control Word 99=704 (connect the Boolean source 704 of RxPDO1 to the local control word input).

For example, Reference Ramp input=708 (connect the Long source 708 of RxPDO1 to the local reference value input).

Chapter 5: System Bus Engineering Planning and Capacity Calculation

Before building the actual system, rigorous engineering planning must be carried out (Chapter 4.14).

5.1 Three Step Planning Method

Define communication relationship: Clarify which TxPDO pairs with which RxPDO (by matching identifiers) to form a data stream.

Establish virtual links: Determine which source data is packaged in each TxPDO, and which target functions are driven by each RxPDO's data.

Capacity check: Calculate the bus load rate to ensure reliable communication.

5.2 Bus load rate calculation

Each PDO frame is fixed at 8 bytes of data, plus protocol overhead, with a maximum frame length of approximately 140 bits. Bus load rate=(sum of transmission times of all TxPDOs)/unit time.

For example, at 1000 kbps, the frame transmission time of a single TxPDO is approximately 140 μ s. If sent at 1ms intervals, the load rate of this PDO is 14%.

Safety limit (Chapter 4.14.3): ≤ 80% (OK), 80-90% (critical),>90% (not feasible, may result in message loss).