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DeltaV Integration with 1769 CompactLogix Controllers Using a ATEN RS-485 to RS-232 Converter
By Jay Chard
Product: IOD-1123 - Allen Bradley DF1 Driver Series 2 Simplex

This application note describes the recommended settings for integrating 1769 CompactLogix controllers using the IOD-1123 Allen Bradley DF1 driver via an ATEN RS-485 to RS-232 Converter.


The following article provides details, requirements and options when connecting Allen Bradley DF1 Simplex Serial Driver to CompactLogix via a RS-485.

This KBA applies to the 1769-L35E CompactLogix 5335E Controller.

The Allen-Bradley Driver communicates with the PLC and updates emulated DeltaV I/O with the data received from the PLC. The primary functions of the driver are listed below:

·        Performs data and message handling between DeltaV and PLC.

·        Sends messages to PLC from DeltaV

·        Processes reply information and updates the corresponding emulated DeltaV I/O channels.

·        Update emulated input channel status and Data Block status to indicate the communication state of PLC.

·        Checks validity of messages received from PLC.

Upon proper installation and configuration of the Allen-Bradley driver within the DeltaV/PSIC system, communications with a correctly configured CompactLogix can be established.


This configuration has only been tested with a simplex system architecture.


DeltaV Configuration

The DeltaV configuration starts with auto-sensing the IO card, where a single Programmable Serial Interface Card (PSIC) is inserted in the designated slot.

Browse the DeltaV I/O tree for the card communicating with the CompactLogix.

Right mouse click on P01 and select Properties.  Check the checkbox to enable this port as shown below.



Click on the Advanced tab.  The following dialog will appear.  Select retry count, message timeout and transmit delay according to their application.  Also, select the Mode as Master.


The parameters under the Communications tab are used to set the Port type, Baud rate, Parity, Data bits, and Stop bits.  Configure these parameters as follows, with the baud rate matching the baud rate on the CompactLogix.


Configure a Serial Device under the enabled port.  Right mouse click and select the New Serial Device menu option.  The following dialog will appear.

Specify the description.  The Device Address is ambiguous because communication will be point-to-point in the PLC. 

Next, configure datasets under the Serial Device.  To add a new dataset, right mouse click on the Serial Device and select New Dataset menu option.  The following dialog will appear:


On the DeltaV tab select the DeltaV data type


On the PLC tab the user will select the device data type, starting address (offset), and number of values.  In the example below, the device data type is 11, which has been tested to work for the CompactLogix L35E processor.


The special data tab is used to specify the file type and number.  In our example, we are reading from N7 data file.  Special Data 1 is 7 to indicate N file type.  And Special Data 2 is 7 for file 7.


Once the Programmable Serial Card has been downloaded, the DeltaV Diagnostics can be used to examine the communication status.  If communications are healthy, the users can view the dataset register values as shown below.


PLC Configuration

Use the RSLogix5000  to configure the channel properties.  We will be connecting the Serial Converter to Ch0 of the CompactLogix via RS-232.

Configure the CompactLogix channel communication parameters as shown below.


Browse over to the System Protocol tab and configure the parameters as follows.


Serial Converter Configuration

Numerous RS-232 to RS-485 Serial Converters exist.  Thus, the configuration parameters of the device will differ from converter to converter.  Communication errors will most likely result from an improper configuration of this device.  MYNAH has successfully tested ATEN’s RS-232 to RS-422 / RS-485 Bidirectional Converter Model: IC-485AI with use in this application.  The configuration for the device was as follows:

Enable the DTE switch on the front of the Device.


The DIP switches on the back of the device should be set as follows for a 9600 baud rate, 10 bits default (1 Start; 8 Data; 0 Parity; 1 Stop), and RS-422 Master:

1. OFF
2. OFF
3. ON
4. OFF
5. OFF
6. ON
7. ON
8. ON



Switches 1 – 3 are used to configure the baud rate setting. 

1. The baud rate must be the same for all units on the installation
2. The default is 9600 bps.


Switches 5 – 6 are used to configure the Data Format.  These two switch segments configure the bit settings for the Start, Data, Parity, and Stop.

Note: The default is 10 bits (1 Start; 8 Data; 0 Parity; 1 Stop). Unless you have a special reason to change this, we recommend that you leave it as is.  If you do change it, however, all the units on the installation must be changed to match.


Switches 7 – 8 are used to configure the operating mode.


Lastly, the following wiring was used:


Please refer to the ATEN Converter user manual for further information on configuring the Device.