Controllogix application, F-41 – Rockwell Automation PLC-5 Fieldbus Solutions for Integrated Architecture User Manual User Manual

Page 289

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Publication 1757-UM006A-EN-P May 2002

1788-CN2FF Installation Example F-41

OUT pin of the SMAR AO block is connected to the fifth input of the
MAI module, on the MAI FB.

There is also the BackCalibration, or BKCAL connections shown from
the SMAR. At present the FFCT software demands that there be a
BKCAL connection to the MAO FB.

This combination of connections will create a ControlNet Object in the
CN2FF that can be sent to controllers using RSNetworks or
ControlBuilder, depending on which controller you are using.

ControlLogix Application

We are now ready to use RSLogix 5000 and RSNetWorx software to set
up and schedule a connection between the ControlLogix system and
the Linking Device. Normally, all data exchanged between the
ControlLogix controller and the CN2FF Linking Device is scheduled.

1. Open RSLogix 5000 software and create a project called CN2FF.

2. Add a 1756-CNB[R]/B to your project in the I/O configuration

folder.

The next step is to add the 1788-CN2FF module to the I/O
configuration below the 1756-CNB[R]/B. However, the RSLogix
5000 software does not currently support the 1788-CN2FF, so we
have to select the generic module connection.

3. Add a CONTROLNET-MODULE connection below the

1756-CNB[R]/B.

This connection will be used for the1788-CN2FF module.

4. Fill in the parameters in the module properties window as

shown in Figure F.5.

IMPORTANT

If a Fieldbus Device becomes disconnected from the
Fieldbus, or suddenly stops transmitting data, or if
the transducer stopped functioning in a transmitter,
and the device could not produce data, the CN2FF
will still retain the last valid value that it received. To
handle this, the Fieldbus Status Byte, and/or the byte
listed as the ControlNet Status Byte will change. It is
absolutely necessary that the control
application program monitor the Status of the
PV
, and take whatever action is appropriate if a PV
so no longer valid.

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