The CRep NM is a compact 2-channel CAN repeater designed for mobile machinery and other space-constrained CAN applications. It transparently regenerates and retransmits CAN signals independent of the CAN protocol in use, enabling flexible CAN network topologies including star and tree structures and longer stub lines. Automatic isolation of permanently dominant CAN bus segments further improves network robustness by limiting the impact of common CAN bus faults, a feature particularly valuable in demanding mobile applications.
Key Features
- Protocol transparent 2-channel CAN repeater
- Low propagation delay
- Shutdown of erroneous bus segments
- Choice of Baud Rate: 10/20/50/125/250/500kBaud (selected at order time via factory set inhibit time)
- Optional 120Ω termination on one or both channels
- Designed and Tested for Demanding Environments
- Rail Mountable
- FCC Class A Verified (use restricted to commercial, business, and industrial environments)
- Backed by 25+ years CAN expertise
Designed and Tested for Demanding Environments
The CRep NM was developed for use in special-purpose vehicles such as construction, agricultural and forestry machinery. Environmental testing was performed to the following standards, during which CAN communication remained stable. Test reports are available on request:
- DIN EN 60068-2-14 — Temperature change
- DIN EN 60068-2-38 — Composite temperature/humidity cycle
- DIN EN 60068-2-27 — Shock
- DIN EN 60068-2-64 — Broadband random vibration
Baud Rate Settings & Overall Cable Length Restrictions
CRepNM repeaters are available in a number of baud rate configurations. The maximum CAN cable length, which is the distance between the furthest two nodes in the network, is related to the operating baud rate as follows:
| Baud Rate | Maximum Cable Length with single CRep NM added When a CRep NM repeater is used, the effect of the propagation delay through the repeater must be included in the cable length calculation. For a CRep NM repeater, the typical and maximum propagation delays is 100ns and 180ns, respectively. Assuming a 5.5ns/m propagation delay for cable, the maximum propagation delay through the CRep NM repeater is equivalent to a cable length of roughly 33m (rounding-up). |
| 500kbit/s | 100 – 33 = 67m |
| 250kbit/s | 250 – 33 = 217m |
| 125kbit/s | 500 – 33 = 467m |
| 50kbit/s | 1000 – 33 = 967m |
Specifications
Layout and Connection
CRep NM devices include 2 CAN segments, wired by a terminal block with 4 clamps. The power supply of CRep NM is separately wired by a terminal block with 2 clamps.
The following table shows the terminal assignment of the power connector:
| Pin | Name | Function |
| 1 | + | Positive supply +24V |
| 2 | – | Ground |
The following table shows the terminal assignment of the CAN connector:
| Pin | Name | Function |
| 3 | H | CAN 1 high bus line |
| 4 | L | CAN 1 low bus line |
| 5 | H | CAN 2 high bus line |
| 6 | L | CAN 2 low bus line |
Limiting Values
| Parameter | Minimal | Maximal | Unit |
| Storage temperature | -20 | +85 | °C |
| Operating temperature | -20 | +85 | °C |
| Supply voltage | -35 | +36 | V |
| Admissible power consumption (at 60°C) | – | 2000 | mW |
| Voltage on bus connections (Note 1) | -25 | +25 | V |
(Note 1) It should be noted that, with an existing termination resistor, the current flowing through it in the event of a fault will not lead to its overload.
Any (also temporary) stress in excess of the limiting values may cause permanent damage on CRep NM and connected devices.
Nominal Values
| Parameter | Minimal | Typical | Maximal | Unit |
| Supply voltage at connector 1 | 10 | 24 | 30 | V |
| Current consumption (running idle) | – | 20 | – | mA |
| Current consumption (250kBaud, 100% busload) | – | 35 | – | mA |
| Propagation delay | – | 100 | 180 | ns |
| Error time | 5 | 6 | 7 | ms |
| Internal termination resistor | 118 | 120 | 122 | Ω |
All values, unless otherwise specified, refer to a supply voltage of 24V and an environmental temperature of 20°C.
