Explicit messaging application examples – Rockwell Automation 1769-ADN Compact I/O 1769-ADN DeviceNet Adapter User Manual

Page 159

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Publication 1769-UM001B-EN-P - October 2002

Appendix

B

Explicit Messaging Application Examples

1756-DNB Explicit
Messaging Application
Example

The following explicit messaging application example details a
1756-DNB DeviceNet scanner controlling 1769 Compact I/O via
DeviceNet and the 1769-ADN DeviceNet Adapter.

While explicit messages are not required when using 1769 I/O on
DeviceNet, these messages allow you to read status information from
the 1769-ADN adapter and 1769 I/O modules as well as write 1769
I/O module configuration parameters while the system is running.

These operations are not required when using the 1769-ADN adapter,
but may be necessary from an application view if, for example, you
need to modify the configuration of an I/O module while the system
is running. Also, in the event of failure, you may need to read status
information from the 1769-ADN or I/O module from a remote
terminal.

Before attempting any explicit messages to a 1769-ADN, the adapter
must be configured in a DeviceNet scanner’s scanlist. This example
uses a 1756-DNB DeviceNet scanner in slot 1 of a 1756 ControlLogix
chassis. The Logix5550 controller is in slot 0. RSLogix 5000
programming software is used to program the Logix5550 controller
and RSNetworx for DeviceNet is used to schedule I/O on DeviceNet.

We’ll cover the following list of message commands in this example:

• Get 1769-ADN Status
• Get 1769 I/O Module Status
• Get 1769 I/O Module Configuration File Size
• Set 1769 I/O Module Configuration
• Save 1769 I/O Module Configuration
• Get 1769 I/O Module Configuration

Get 1769-ADN Status

Use a “CIP Generic” MSG instruction to send any explicit message to a
1769-ADN or 1769 I/O module from a Logix5550 controller via a
1756-DNB DeviceNet scanner. You’ll see in the ladder logic example
to follow, a CIP Generic message is sent to the 1756-DNB scanner and
ultimately to the 1769-ADN.

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