Rockwell-automation 1769-L23E-QB1B_L23E-QBFC1B_L23-QBFC1B CompactLogix Manual de usuario descargar pdf (Pagina 176)

176 Publication IASIMP-QS010B-EN-P - October 2009

Chapter 2 Network Communication

Modbus Support

To use Logix5000 controllers with the Modbus protocol, connect the

controllers through the serial port and execute specific ladder logic routines.

A sample controller project is available with RSLogix 5000 Enterprise

programming software by clicking Help and choosing Vendor Sample Projects.

Broadcast Messages Over a Serial Port

You can broadcast messages over a serial port connection from a master

controller to all of its slave controllers by using several communication

protocols. Those protocols are the following:

• DF1 Master

• DF1 Radio Modem

• DF1 Slave

Broadcasting over a serial port is achieved using the ‘message’ tag. Because

messages are sent to receiving controllers, only the ‘write’ type messages can

be used for broadcasting.

The broadcast feature can be set up by using ladder logic or structured text.

The broadcast feature can also be set by modifying the path value of a message

tag in the tag editor.

For this example, ladder logic programming software will be used.

Step 1: Set Broadcast - Controller Properties

First, set the System Protocol by following these steps.

1. In the Controller Organizer, right-click the controller and choose

Properties.

1 2 ... 171 172 173 174 175 176 177 178 179 180 181 ... 248 249

Sin comentarios

Rockwell-automation 1769-L23E-QB1B_L23E-QBFC1B_L23-QBFC1B CompactLogix Manual de usuario Pagina 176