Image is for illustrative purposes only. Please refer to product description.
- Manufacturer
- Allen-Bradley
- Manufacturer part number
- 1756-CNB
- Product family
- ControlLogix Communication Modules (1756)
- Technical datasheet
- Data sheet
Specifications
| Attribute | Value |
|---|---|
| Type | ControlNet communication module |
| Manufacturer lifecycle | Discontinued |
| OEM successor | 1756-CN2 |
| Communication | ControlNet |
| Interface | 1 ControlNet BNC |
| Number Of Channels | 1 |
| Conducted RF immunity | 10V rms with 1 kHz sine-wave 80% AM from 150 kHz...80 MHz |
| Connections supported, max | 64 maximum |
| ControlNet cable | 1786-RG6 quad shield RG6 coaxial cable |
| ControlNet port | 1 ControlNet BNC |
| Current draw | 970mA @ 5.1V DC, 1.7mA @ 24V DC |
| EFT/B immunity | ±3kV @ 5kHz on ControlNet ports |
| Emissions | CISPR 11: Class A |
| Enclosure type rating | None (open-style) |
| ESD immunity | 6 kV contact discharges, 8 kV air discharges |
Show all 36 specificationsShow fewer specifications
| Isolation voltage | Standard: 30V (continuous), basic insulation type, ControlNet network to, backplane, Redundant: 30V (continuous), basic insulation type, ControlNet A/B to, backplane, and ControlNet A to ControlNet B, USB to backplane and USB to ControlNet, No isolation b |
|---|---|
| Logix communication connections range | 40...48 |
| Module location | Chassis based, any slot |
| NAP cable | 1786-CP |
| NAP port | 1 NAP RJ45 |
| Number of nodes, max | 99 nodes |
| Operating temperature | 0 to 60 °C |
| Power dissipation | 5.1 W |
| Radiated RF immunity | 10 V/m with 1 kHz sine-wave 80% AM from 80...2000 MHz, 10 V/m with 200 Hz 50% Pulse 100% AM @ 900 MHz, 10 V/m with 200 Hz 50% Pulse 100% AM @ 1890 MHz, 3 V/m with 1 kHz sine-wave 80% AM from 2000...2700 MHz |
| Relative humidity | 5...95% noncondensing |
| Shock | Operating: 30 G, Non operating: 50 G |
| Slot width | 1 |
| Storage temperature | -40 to 85 °C |
| Supporting protocol for other bus systems | Yes |
| Surge transient immunity | ±2 kV line-earth (CM) on ControlNet ports |
| Surrounding air temperature, max | 60 °C |
| Thermal dissipation | 17.4 btu/h |
| Transmission rate | 5000 kbps |
| Vibration | 2 G @ 10...500 Hz |
| Weight, approx | 0.26 kg |
| Wiring category | 1 - on ControlNet ports, 3 - on NAP ports |
Description
The Allen-Bradley 1756-CNB is a ControlLogix Communication Module for ControlNet, according to Rockwell Automation's product data. Rockwell lists one ControlNet BNC interface, one channel, a transmission rate of 5000 kbps, a maximum of 99 nodes and a maximum of 64 connections. It is chassis based, occupies one slot and can be fitted in any slot, and it also has one NAP RJ45 port. Rockwell gives the lifecycle status as Discontinued and names the 1756-CN2 as the replacement, with the category Engineering Replacement.
Application: Communication module
Used with: ControlLogix 1756 chassis
What is the 1756-CNB used for?
The 1756-CNB connects a ControlLogix chassis to a ControlNet network. Rockwell specifies 1786-RG6 quad shield RG6 coaxial cable for the ControlNet port and 1786-CP cable for the NAP port. It is used where a chassis-based ControlLogix system needs to communicate over ControlNet.
Key features
- One ControlNet BNC port, single channel
- Transmission rate of 5000 kbps
- Up to 99 nodes and 64 connections
- Chassis based, any slot, one slot wide
- Operating temperature 0 to 60 °C
Documents and Resources
OEM successor to 1756-CNB
1756-CN2 is named by Allen-Bradley as the successor. It is an upgrade, not a like-for-like spare: check wiring, I/O and configuration for your installation before ordering it. Contact sales@timcontrols.com if you need one.
Associated Products
| Image | Product | Description | Stock | View | Add to RFQ |
|---|---|---|---|---|---|
 | 1756-CN2Allen-Bradley | ControlLogix ControlNet interface module, BNC | In stock | View | |
 | 1756-CN2RAllen-Bradley | ControlLogix ControlNet redundant interface module | In stock | View | |
 | 1756-CN2RXTAllen-Bradley | ControlLogix ControlNet redundant interface module, XT | In stock | View | |
 | 1756-CNBRAllen-Bradley | ControlLogix ControlNet communication module, redundant | In stock | View | |
 | 1756-DNBAllen-Bradley | ControlLogix DeviceNet bridge and scanner module | In stock | View | |
 | 1756-EN2FAllen-Bradley | ControlLogix EtherNet/IP module, 100 Mbps multimode fiber | In stock | View | |
 | 1756-EN2TAllen-Bradley | ControlLogix EtherNet/IP communication module, 10/100 Mbps | In stock | View | |
 | 1756-EN2TRAllen-Bradley | ControlLogix EtherNet/IP module, dual port 10/100 Mbps | In stock | View | |
 | 1756-EN2TXTAllen-Bradley | ControlLogix EtherNet/IP module, extended temperature | In stock | View | |
 | 1756-EN3TRAllen-Bradley | ControlLogix EtherNet/IP module, dual port copper | In stock | View | |
 | 1756-ENBTAllen-Bradley | ControlLogix EtherNet/IP communication module, 10/100 Mbps | In stock | View | |
 | 1756-CN2RKAllen-Bradley | ControlLogix Redundant ControlNet Module, Conformal Coated | In stock | View |
Product Questions
Is the 1756-CNB discontinued?
Yes. Its manufacturer lifecycle status is Discontinued.
Is there a replacement for the 1756-CNB?
The 1756-CN2 is named by Allen-Bradley as the successor. It is an upgrade, not a like-for-like spare: check ratings, wiring and configuration before ordering it in its place.
Do you ship worldwide?
Yes. TimControls ships worldwide. Parts usually ship within 3 to 7 working days of order confirmation, and the exact lead time and shipping options are stated on your quote. Include your delivery country and postal code when you ask for a quote.
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