Yaskawa Sigma II Series NS300 DeviceNet Application Module Deep Technical Guide

Screw fastening: Depending on the driver model, use the accompanying M3 or M4 screws to secure it. The manual emphasizes that for rack mounted drives, spring washers and flat washers must be used, otherwise the grounding screw may protrude from the back of the flange, hindering the smooth installation of the drive.

3.2 Environmental thermal management and spacing control

Servo drives are high-power power electronic devices, and thermal management is crucial. After installing the NS300 module, the overall thermal design of the drive should follow the following principles:

Vertical installation: The driver must be installed perpendicular to the wall to ensure natural air convection.

Installation spacing:

Up and down space: Reserve at least 50mm of space to facilitate air circulation.

Left and right spacing: When installed side by side, modules should have a spacing of at least 10mm between them.

Cabinet environment: Cooling fans need to be installed inside the control cabinet to ensure that the ambient temperature does not exceed 55 ° C. It is recommended to maintain long-term reliability below 45 ° C.

DeviceNet Network Topology and Cabling Specification

This is the core part of this technical guide. DeviceNet, as a fieldbus based on CAN bus, has extremely high requirements for signal integrity in its physical layer design. Incorrect wiring is the main cause of communication interruption, packet loss, or device failure.

4.1 Network Topology Structure

The DeviceNet network consists of trunk and branch lines, supporting T-shaped branch and multi branch hybrid topologies.

Node: As a node on the network, the NS300 module can be either a master station or a slave station. The network supports a maximum of 64 nodes (addresses 0-63).

Terminal resistors: In order to eliminate signal reflection, terminal resistors must be installed at both ends of the main line. This is the most easily overlooked but crucial rule. Lack of terminal resistance can cause waveform distortion in communication, especially in high-speed communication (500kbps).

4.2 Connector Interface Definition (CN6)

NS300 adopts a 5-pin open connector, and the pin definition strictly follows the ODVA standard:

Pin 1 (V -, Black): 0V communication power supply

Pin 2 (CAN L, Blue): CAN low-level signal line

Pin 3 (SHIELD, Drain): Shielding layer connection

Pin 4 (CAN H, White): CAN high-level signal line

Pin 5 (V+, Red): 24V communication power supply

Attention: The communication power supply must be independently provided by an external source, and the control power supply of the servo drive cannot be borrowed to avoid power noise interference with the communication bus.

4.3 Cable selection and length limitations

DeviceNet cables are divided into thick and thin cables, and the selection directly determines the maximum coverage range of the network.

Baud rate, maximum length of coarse cable, maximum length of fine cable, total branch length limit

500 Kbps 100 m 100 m 39 m

250 Kbps 250 m 100 m 78 m

125 Kbps 500 m 100 m 156 m

Coarse cable: With low signal attenuation, it is suitable for long-distance backbone transmission, but it has high hardness and is not easily bent.

Thin cable: Good flexibility, suitable for short distance branch connections, but with significant signal attenuation.

Hybrid cabling calculation formula: When there are both thick and thin cables in the network, their lengths must satisfy specific linear constraint relationships. For example, at a baud rate of 125 Kbps: L_thick cable+5.0 × L_thin cable ≤ 500 meters. This formula reveals the "weighted" negative impact of thin cables on network length, which engineers must perform precise calculations when planning cabling.

4.4 Branch Line Length Rules

Single branch line restriction: The maximum length from the branch point of the main line to the node cannot exceed 6 meters.

Cumulative branch line limit: The total length of all branch lines on the network must be within the specified range (such as a total length of no more than 39 meters at 500 Kbps). Excessive accumulation of branch lines can lead to signal reflection and impedance mismatch.

4.5 Grounding strategy and anti-interference

Single point grounding: The shielding layer of the communication cable should be connected to the FG terminal of the communication power supply and finally grounded (with a grounding resistance of less than 100 Ω).

Prohibition of multiple grounding points: Multiple grounding points can form a ground loop and introduce significant noise interference.

Independent grounding: The grounding point of the DeviceNet network should not be shared with the grounding point of the servo drive or frequency converter to avoid interference from the ground current of strong electrical equipment on weak electrical communication signals.

Software configuration and EDS files

To make the NS300 module work properly on the network, in addition to physical wiring, software level configuration is also required.

5.1 Parameter Settings

When NS300 is installed on SGDH and powered on for the first time, the driver parameters will be automatically set to adapt to the application module. But before formal operation, users need to set the node address and baud rate by rotating the switch, and ensure that these settings are consistent with the configuration of the upper computer master station.