Allen-Bradley ControlLogix User Manual

1756-6.5.3 - December 1999
Allocating Communication Connections A-3
If the module configuration is appropriate for the I/O module found in the
slot, a connection is made and operation begins. If the module configuration
is not appropriate, the connection is rejected. You can view the fault
message on the Connection tab of the module’s properties. Module
configuration can be inappropriate for any of a number of reasons (for
example, a mismatch in electronic keying that prevents normal operation).
In this example, the owner controller has three direct connections with I/O
modules in the remote chassis.
The local controller in this example uses these bidirectional connections:
When you select the communication format for the I/O module, the owner
and listen-only formats are direct connections.
Rack optimized connections for I/O modules
When a digital I/O module is located in a remote chassis (with respect to its
owner), you can select rack optimized communication. A rack optimized
connection consolidates connection usage between the owner and the digital
I/O in the remote chassis. Rather than having individual, direct connections
for each I/O module, there is one connection for the entire chassis.
Using Direct Connections with I/O in a Remote Chassis
Owner Logix 5550
ControlNet
Slot 1 RPI = 5mS
Slot 2 RPI = 50mS
Slot 3 RPI = 25mS
ControlNet
Local chassis Remote chassis
I
N
P
U
T
I
N
P
U
T
O
U
T
P
U
T
ControlNet
I
N
P
U
T
O
U
T
P
U
T
Interface module
Interface Module
Controller
Connection Type Module Quantity Connections
per Module
Total
Connections
Logix5550 controller to local I/O module
2 1 2
Logix5550 controller to remote I/O module
3 1 3
Logix5550 controller to remote 1756-CNB module
1 1 1
Total 6

Allen-Bradley ControlLogix Specifications

General

Communication	EtherNet/IP, ControlNet, DeviceNet, DH+
I/O Capacity	Up to 128, 000 I/O points (varies by configuration)
Redundancy	Supported (with specific modules)
Programming Software	Rockwell Automation Studio 5000 Logix Designer
Operating Temperature	0°C to 60°C (32°F to 140°F)
Programming Languages	Ladder Logic, Function Block Diagram, Structured Text, Sequential Function Chart
Modularity	Yes
Certifications	UL, CE
Processor Type	Multiple options available, including standard, safety, and extreme environment processors
Power Supply	Multiple options available, including standard and redundant power supplies with various voltage ranges (e.g., 24V DC, 120/240V AC)