Ethernet slip rings
Senring Industrial bus slip rings (BM/BH)
Signal slip rings for fieldbus and Ethernet, listed for PROFIBUS, CANbus, DeviceNet, ControlNet, RS-232/422/485, USB and 10/100/1000BASE-T Ethernet, in solid-shaft (BM) and through-bore (BH, up to 50 mm) versions with up to 168 circuits and 690 V.
Key specifications
| Circuits (max) | 168 |
|---|---|
| Voltage (max) | 690 V |
| Bore (max) | 50 mm |
| Outer diameter | 56–130 mm |
| Data / bus | Ethernet 10/100/1000BASE-T, PROFIBUS, CANbus, DeviceNet, ControlNet, LonWorks, RS-232, RS-422, RS-485, USB |
Summarised in our own words from SENRING Electronics Co., Limited's published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1
Notes on this data
Current, speed and IP not published per model.
Specify Motion is not affiliated with SENRING Electronics Co., Limited. Senring and Industrial bus slip rings (BM/BH) are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a Senring part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These series from our supply network is the closest match on published figures.
Slip rings with dedicated 100M or Gigabit Ethernet channels alongside power and signal circuits, offered in solid-shaft and through-bore forms.
| Published maximum | Industrial bus slip rings (BM/BH) | Ethernet Slip Ring |
|---|---|---|
| Circuits | 168 | 100 |
| Current per circuit | — | 30 A |
| Speed | — | 300 rpm |
| Voltage | 690 V | 240 V |
| Bore | 50 mm | 100 mm meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What an ethernet slip ring is
An Ethernet slip ring is a rotary joint designed to pass industrial Ethernet, such as 100 Mbit/s or gigabit links, through continuous rotation without unacceptable packet loss. The data rings are laid out as matched pairs with controlled impedance, short stubs and screening from power rings, and the brushes are chosen for low, stable contact resistance. Some units use contactless capacitive, inductive or optical channels for the highest rates. Most combine the Ethernet channels with power and discrete signal rings in one housing.
When engineers choose an ethernet slip ring
Choose an Ethernet slip ring when the rotating part carries cameras, drives, remote I/O or sensors on a network, which cuts the ring count compared with hard-wiring every signal. It suits indexing machines, packaging turrets and gimbals running EtherCAT, PROFINET or EtherNet/IP. The trade-offs are cost and validation: contact rings add small resistance changes, and gigabit links are more sensitive than 100 Mbit/s. For very high data rates, long life or high speed, a fibre optic or contactless channel may be better.
How to specify the Senring Industrial bus slip rings (BM/BH)
Send these with your enquiry and an engineer can confirm the right Industrial bus slip rings (BM/BH) variant or an equivalent:
- Protocol and data rate, such as EtherCAT, PROFINET or gigabit Ethernet
- Number of Ethernet channels and pairs per channel
- Required test standard or bit error rate target
- Power circuits and current per circuit (A)
- Speed (rpm) and expected life (revolutions)
- Cable type and connectors on each side, such as RJ45 or M12
- Cable lengths to the nearest switch or node (m)
Common mistakes to avoid
- Specifying gigabit when the network only needs 100 Mbit/s, which adds cost and complexity
- Ignoring the cable runs on each side, which count towards the total channel length and loss
- Routing motor power next to data rings without screening or separation
- Not testing the full link with the real protocol under rotation before production
Senring Industrial bus slip rings (BM/BH): frequently asked questions
What is the Senring Industrial bus slip rings (BM/BH)?
Signal slip rings for fieldbus and Ethernet, listed for PROFIBUS, CANbus, DeviceNet, ControlNet, RS-232/422/485, USB and 10/100/1000BASE-T Ethernet, in solid-shaft (BM) and through-bore (BH, up to 50 mm) versions with up to 168 circuits and 690 V. Published series figures include circuits 168, voltage 690 V, bore 50 mm, outer diameter 56 mm. It is made by SENRING Electronics Co., Limited; Specify Motion can help source it or propose an equivalent.
Who makes the Senring Industrial bus slip rings (BM/BH)?
The Senring Industrial bus slip rings (BM/BH) is made by Senring (SENRING Electronics Co., Limited) and is listed here for engineers comparing options. Specify Motion is not affiliated with SENRING Electronics Co., Limited; brand names are used only to identify the product.
What is the circuits of the Senring Industrial bus slip rings (BM/BH)?
The published series maximum circuits is 168. Individual models and sizes in the Industrial bus slip rings (BM/BH) range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the Senring Industrial bus slip rings (BM/BH)?
Yes. On published figures, Ethernet Slip Ring is the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
Can EtherCAT and PROFINET run through a slip ring?
Yes, when the slip ring is designed for it. Real-time protocols are sensitive to link drops, so the data rings need controlled impedance, good screening and stable contact resistance. Tell the supplier the protocol, cycle time and number of nodes on the rotating side, and test the full network under rotation. Many suppliers validate their Ethernet rings against standard cabling test methods.
What is the difference between a contact and a contactless Ethernet slip ring?
A contact slip ring passes the signal through brushes on rings, which is economical and handles 100 Mbit/s and often gigabit links well. A contactless channel uses capacitive, inductive or optical coupling, so there is no wear on the data path and very high rates or speeds are possible. Contactless channels cost more and usually still need contact rings for power.
Further reading: Ethernet through slip rings · How to select a slip ring · Slip rings
Other ethernet slip rings series
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