Omega Engineering OMG-CONV-485-ISO manual System Installation, Please Note

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Installation

System Installation

The OMG-CONV-485-ISO can be connected to any existing RS-232 port. A cable such as the CA-177can be used to attach the OMG-CONV-485-ISO DB-25F to the PC’s DB-9M connector.

1.Locate an existing RS-232 COM: port and connect the OMG-CONV-485-ISO.

2.With the OMG-CONV-485-ISO case open, configure dip switches SW1 and SW2 for your application.

3.Connect the wiring to your external device via the provided 6-position screw terminal. The signals are labeled on the board’s silk screen. From the included hardware, select the strain relief clamp that best fits your cable.

4.Make sure all connections are secure and that strain relief is correctly installed.

5.Close the OMG-CONV-485-ISO case and connect the included AC adaptor.

6.If the OMG-CONV-485-ISO is in RS-422 mode, the EN led should now be on since the transmitter is always enabled.

Installation is complete.

Please Note:

On power-up, the OMG-CONV-485-ISO scans the Mode Select dip switch (SW1) one time to determine the communication mode and then branches to the selected control logic. No attempt is made to periodically check the switch for a mode change. This is done for two reasons. First, our experience shows that a device such as this is configured for the required application and the mode is not changed after this. Due to this reason, the product is not burdened with the overhead of always checking this switch. At higher baud rates this becomes especially critical due to the speed of the onboard microcontroller. The utmost priority is given to sampling the incoming data.

What this means?

If the OMG-CONV-485-ISO has been configured for a particular mode, and for some reason it has become necessary to change the communication mode, remove power, reconfigure the Mode Select dip switch (SW1) for the new mode, and reapply power.

OMG-CONV-485-ISO

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Contents User’sGuide Mexico CanadaBenelux Czech RepublicContents Figures Introduction Factory Default SettingsOverview What’s IncludedRS-485 Enable Modes Card SetupDip switch SW1, RS-422 Communication Mode Examples Dip switch SW1Function Line Termination and Receiver Echo Off/OnRS-422 with Termination and Receiver Echo Electrical Interface Examples Dip switch SW2 Operating System Installation For Windows Users RS-485 Two-Wire and RS-485 Four-Wire Slave Installation Other Operating Systems Please Note System InstallationTechnical Description Connector Pin Assignments RS-232 Signals DB-25 FemaleRS-422/485 Pin Assignments 6 Position Screw Terminal Environmental Specifications SpecificationsPhysical Dimensions ManufacturingAppendix a Troubleshooting Appendix B How To Get Assistance RS-232 Appendix C Electrical InterfaceRS-422 RS-485 Appendix D Ground Loop Phenomenon What is Ground Loop?Cabling Recommendations Isolated AdapterAppendix E Asynchronous Communications Asynchronous Communications Bit DiagramAppendix F Silk-Screen 688Appendix G Compliance Notices WARRANTY/DISCLAIMER Temperature