Chapter
1
Overview
This chapter provides an overview of communication between the
CompactLogix and MicroLogix 1500 programmable controllers and
DeviceNet devices via the 1769-SDN scanner module. The configuration data tables and the RSNetWorx for DeviceNet screens and windows used to configure the data tables are also described.
The following table identifies what this chapter contains and where to find specific information.
For information about
What You Need to Know
Identify Module Features
What Your Scanner Does
Communicating with Your Slave Devices
1769-SDN Module Data Tables
RSNetWorx Software as a Configuration Tool
See page
1-1
1-2
1-3
1-4
1-5
1-6
What You Need to Know
Before configuring your scanner, you must understand:
• the data exchange between the programmable controller and
DeviceNet devices through the scanner
• user-configurable scanner data tables
• the role of RSNetWorx software
These topics are covered briefly in this chapter and in more detail throughout the rest of the manual.
1
Allen-Bradley Drives
Publication 1769-UM009B-EN-P - May 2002
1-2 Overview
Identify Module Features
Use the following figure to identify the features of the scanner.
2A
1 3A
8B
8A 4
8B
5
9
7A
6
2B
3B
7B
Table 1.1
8A
8B
9
5
6
7A
7B
2B
3A
3B
4
Item
1
2A
Description bus lever (with locking function) upper DIN rail latch lower DIN rail latch upper panel mounting tab lower panel mounting tab
Module and Network status LEDs
Address and Error numeric display grounding screw
DeviceNet mating male receptacle removable DeviceNet female connector movable bus connector with female pins bus connector with male pins nameplate label
Publication 1769-UM009B-EN-P - May 2002
Overview 1-3
What Your Scanner Does
In a typical configuration, the scanner acts as an interface between
DeviceNet devices and the programmable controller.
CompactLogix Controller with
1769-SDN Scanner Module
DeviceNet Network
MicroLogix 1500 Controller with
1769-SDN Scanner Module
PC with RSNetWorx for DeviceNet software
1770-KFD PC
Communication
Module
Series 9000
Photoeye
RediSTATION
DANGER DANGER
MicroLogix 1000 Controller
Connected via 1761-NET-DNI
MicroLogix 1200 Controller
Connected via 1761-NET-DNI
1305 Drive Connected via 1203-GU6
Enhanced DeviceNet Communications Module
The scanner communicates with DeviceNet devices over the network to:
• read inputs from slave devices
• write outputs to slave devices
• communicate with peer devices (messaging)
• upload/download programs to a 1764-LRP based MicroLogix
1500 controller across a DeviceNet network
Allen-Bradley Drives
Publication 1769-UM009B-EN-P - May 2002
1-4 Overview
Communicating with Your
Slave Devices
The scanner communicates with devices via strobe , poll , change of state , and/or cyclic I/O messages. It uses these messages to solicit data from or deliver data to each device. Data received from the devices, or input data, is organized by the scanner and made available to the controller. Data sent from your controller, or output data, is organized in the scanner and sent on to your devices.
•
A strobe message is a multicast transfer of data (which is 64 bits in length) sent by the scanner that initiates a response from each strobed slave device. The strobe devices respond with their data, which can be as much as 8 bytes of information. As a slave device, the scanner does not support the strobe message.
•
A poll message is a point-to-point transfer of data (0 to 128 bytes) sent by the scanner to the slave device. The poll message also initiates a response from each poll slave. The slave device responds with its input data (0 to 128 bytes).
•
A change of state message is a transfer of data sent whenever a data change occurs. A user-configurable heartbeat rate allows devices to indicate proper operation during intervals between data changes.
•
A cyclic message is a transfer of data sent at a specific user-configurable rate, such as every 50 ms.
IMPORTANT
Throughout this document, input and output are defined from the controller’s point of view. Output is data sent from the controller to a device. Input is data collected by the controller from a device.
In addition to I/O messaging, the scanner also supports PCCC and CIP explicit messaging, defined later in this manual.
Publication 1769-UM009B-EN-P - May 2002
1769-SDN Module Data
Tables
Overview 1-5
To manage the flow of data between your controller and network devices, the scanner uses input and output data images to transfer data, status and command information between the scanner and the controller.
The basic structure is shown below. See Chapter 5 for more detailed
information.
Input Data Image
The input data image is transferred from the scanner module to the controller across the Compact I/O bus.
Table 1.2 Input Data
Word
0 to 65
66 to 245
Description
Status Structure
DeviceNet Slave Inputs
Data Type
66-word array
180-word array
Output Data Image
The output data image is transferred from the controller to the scanner module across the Compact I/O bus.
Table 1.3 Output Image
Word
0 and 1
2 to 181
Description
Module Command Array
DeviceNet Slave Outputs
Data Type
2-word array
180-word array
Table 1.4 Module Command Array Bit Assignments
Word
0
1
2
3
Bit
0
1
4
5 to 15
0 to 15
Operating Mode
1 = Run, 0 = Idle
1 = Fault
1 = Disable Network
Reserved
(1)
1 = Reset
Reserved
(1)
Reserved
(1)
(1)
DO NOT manipulate Reserved Bits. Doing so may interfere with future compatibility.
Allen-Bradley Drives
Publication 1769-UM009B-EN-P - May 2002
1-6 Overview
RSNetWorx Software as a
Configuration Tool
RSNetWorx is used to configure the scanner’s slave devices. This software tool connects to the scanner over the DeviceNet network via an RS-232 interface (1770-KFD module) or PC Card (1784-PCD or
-PCID).
The recommended configuration software is RSNetworx for DeviceNet
(version 3.00 or higher).
TIP
If your RSNetWorx configuration software does not include the required EDS (Electronic Data Sheet) file, it is available via http://www.ab.com/networks/eds.
Register the new EDS file using the EDS Wizard in
RSNetWorx. Access the wizard from the Tools pull-down menu.
This configuration tool allows you to identify all of the DeviceNet devices and their locations in your system.
TIP
The controller must be in the Program mode, or the scanner in the Idle mode (bit 0 of the Module
Command Array = 0), for the scanner to accept the configuration information.
The following configuration screen map shows the RSNetWorx screens used to configure the scanner.
For more detailed information, see:
•
Chapter 4, Configuring the DeviceNet Network
•
Chapter 6, Using the 1769-SDN Scanner Module with
CompactLogix Controllers
•
Chapter 7, Using the 1769-SDN Scanner Module with MicroLogix
Controllers
Publication 1769-UM009B-EN-P - May 2002
The main RSNetWorx screen.
Overview 1-7
Figure 1.1 RSNetWorx Configuration Screen Map
To browse the network, click on the Online button and select the driver.
To access the 1769-SDN Scanner Module, double-click on the 1769-SDN icon.
To access the scanlist, click on the Scanlist tab.
Move the device into the scanlist.
To download the scanlist, click on the Download to Scanner button.
To edit a device’s I/O parameters, double-click on the device in the scanlist.
To automatically map input devices, select the Input tab and click on the AutoMap button.
To automatically map output devices, select the Output tab and click on the AutoMap button.
Allen-Bradley Drives
Publication 1769-UM009B-EN-P - May 2002
1-8 Overview
Notes:
Publication 1769-UM009B-EN-P - May 2002