Справочник Пользователя для National Instruments NI-DNET

Cables should meet the requirements of the DeviceNet cable specification. 
DeviceNet cabling requirements can be found in the DeviceNet 
Specification.

Belden cable (3084A) meets all of those requirements and should be 
suitable for most applications.

The allowable cable length is affected by the characteristics of the cabling 
and the desired bit transmission rates. Detailed cable length requirements 
can be found in the DeviceNet Specification.

Table B-2 lists the DeviceNet cable length specifications.

The maximum number of devices that you can connect to a DeviceNet port 
depends on the electrical characteristics of the devices on the network. If all 
of the devices on the network meet the DeviceNet specifications, 
64 devices may be connected to the network.

Table B-2.  DeviceNet Cable Length Specifications

500 kb/s

100 m (328 ft)

6 m (20 ft)

39 m (128 ft)

250 kb/s

250 m (820 ft)

6 m (20 ft)

78 m (256 ft)

125 kb/s

500 m (1640 ft)

6 m  (20 ft)

156 m (512 ft)