1756-CNB

Technical specifications

Manufacturer

Allen-Bradley

Manufacturer part no.

1756-CNB

Type

ControlNet communication module

Application

Communication module

Used with

ControlLogix 1756 chassis

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

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

Technical documents (1)

• Rockwell Automation technical data 1756-TD003

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

About the Allen-Bradley 1756-CNB

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.

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.

Lifecycle and successor

Discontinued.

OEM successor: 1756-CN2

Before you order

What to photograph or confirm so the right unit is quoted.

Check that the catalog number on the module label reads 1756-CNB, and note the series letter and firmware revision printed on the same label. If you are unsure, send us a photo of the label and we will help confirm the part.