1756-CN2

Technical specifications

Manufacturer

Allen-Bradley

Manufacturer part no.

1756-CN2

Type

ControlNet communication module

Application

Communication module

Used with

ControlLogix 1756 chassis

Communication

ControlNet

Interface

1 ControlNet BNC

Conducted RF immunity

10V rms with 1 kHz sine-wave 80% AM from 150 kHz...80 MHz

Connections supported, max

131 maximum

ControlNet cable

1786-RG6 quad shield RG6 coaxial cable

ControlNet port

1 ControlNet BNC

Current draw

1100mA @ 5.1V DC, 3mA @ 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

128

Module location

Chassis based, any slot

Number of nodes, max

99 nodes

Operating temperature

0 to 60 °C

Power dissipation

5.6 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, Nonoperating: 30 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

Technical documents (1)

• Rockwell Automation technical data 1756-TD003

Key features

• One ControlNet BNC interface at 5000 kbps
• Up to 99 nodes and 131 connections maximum
• Chassis based, any slot, one slot wide
• Operates 0 to 60 °C, 5 to 95% noncondensing humidity
• Open-style enclosure, approx. 0.26 kg

About the Allen-Bradley 1756-CN2

The Allen-Bradley 1756-CN2 is a ControlLogix Communication Module, described by Rockwell Automation as a ControlNet Interface Module (100 connections). Rockwell's product data gives a ControlNet transmission rate of 5000 kbps, one ControlNet BNC port, a maximum of 99 nodes and a maximum of 131 connections. It is chassis based, fits any slot, is one slot wide and has an open-style enclosure with no enclosure type rating. Rockwell lists its lifecycle status as Active Mature, with a current draw of 1100mA @ 5.1V DC and 3mA @ 24V DC.

What is the 1756-CN2 used for?

The 1756-CN2 gives a ControlLogix chassis an interface to a ControlNet network. Rockwell specifies 1786-RG6 quad shield RG6 coaxial cable for the ControlNet connection, and lists 128 Logix communication connections. It is used in chassis-based control systems where devices communicate over ControlNet.

Lifecycle and successor

Active.

Before you order

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

Check that the catalog number 1756-CN2 on the module label matches your part, and note the series letter and firmware revision printed there. If you are unsure, send us a photo of the label and we will check it against your requirement.