Spectrum Controls 1756sc-CTR8 - Manual (Page 24)

Operation Within the
ControlLogix System
This chapter describes how the 1756sc-CTR8 analog module works
within the ControlLogix system. This chapter covers:
• Ownership and connections to the module
• Direct connections
• Listen only mode
• Configuration changes with multiple owners.
Ownership and
Connections
Every I/O module in the ControlLogix system must be owned by a
Logix5550 Controller to be useful. This owner-controller stores
configuration data for every module that it owns and can be local or
remote in regard to the I/O module’s position. The owner sends the I/O
module configuration data to define the module’s behavior and begin
operation within the control system. Each ControlLogix I/O module must
continuously maintain communication with its owner to operate normally.
Typically, each module in the system will have only 1 owner. Input
modules can have more than 1 owner. Output modules, however, are
limited to a single owner.
Using RSNetWorx
and RSLogix 5000
The I/O configuration portion of RSLogix5000 generates the
configuration data for each I/O module in the control system, whether
the module is located in a local or remote chassis. A remote chassis, also
known as networked, contains the I/O module but not the module’s
owner controller. Configuration data is transferred to the controller during
the program download and subsequently transferred to the appropriate I/
O modules. I/O modules in the same chassis as the controller are ready
to run as soon as the configuration data has been downloaded. You must
run RSNetWorx to enable I/O modules in the networked chassis.
Running RSNetWorx transfers configuration data to networked modules
and establishes a Network Update Time (NUT) for ControlNet that is
compliant with the desired communications options specified for each
module during configuration. If you are not using I/O modules in a
networked chassis, running RSNetWorx is not necessary. However,
anytime a controller references an I/O module in a networked chassis,
RSNetWorx must be run to configure ControlNet. Follow these general
guidelines when configuring I/O modules:
Chapter 3