Omega OMG-CONV-485-ISO - Manual

Introduction OMG-CONV-485-ISO Page 1 Introduction Overview The OMG-CONV-485-ISO is a single channel RS-232 to RS-422/485 asynchronous converter. It provides one field selectable RS-422/485 serial port supporting asynchronous data rates up to 115.2K bps. The OMG-CONV-485- ISO is self-powered allowing...

Card Setup OMG-CONV-485-ISO Page 2 Card Setup RS-485 Enable Modes RS-485 is ideal for multi-drop or network environments. RS-485 requires a tri-state driver that will allow the electrical presence of the driver to be removed from the line. The driver is in a tri-state or high impedance condition whe...

Card Setup OMG-CONV-485-ISO Page 3 Communication Mode Examples (Dip switch SW1) O N 12 OFF Figure 1- Dip switch SW1, RS-422 O N 12 OFF Figure 2 – Dip switch SW1, RS-485 ‘Auto’ Enable O N 12 OFF Figure 3 – Dip switch SW1, RS-485 ‘RTS’ Enable O N 12 OFF Figure 4 – Dip switch SW1, RS-485 ‘Data’ Enable

Card Setup OMG-CONV-485-ISO Page 4 Line Termination and Receiver Echo Off/On Typically, each end of the RS-485 bus must have a line-terminating resistor (RS-422 terminates at the receive end only). A 120-ohm resistor is across each RS-422/485 input in addition to a 1K-ohm pull-up/pull-down combinati...

Card Setup OMG-CONV-485-ISO Page 5 Electrical Interface Examples (Dip switch SW2) O N 12 OFF 3 456 Figure 6 – RS-422 with Termination and Receiver Echo O N 12 OFF 3 456 Figure 7 – RS-485 2 -wire with Termination and Receiver No Echo O N 12 OFF 3 456 Figure 8 – RS-485 2 -wire no Termination and Recei...

Installation OMG-CONV-485-ISO Page 6 Operating System Installation (For Windows Users) RS-422/RS-485 Four Wire Master/RS-485 Two Wire Auto Mode Installation If your application is 4-wire Full Duplex RS-422 or 4-Wire RS-485 Master, where control of the transmitter is not required, or 2-wire RS-485 an...

Installation OMG-CONV-485-ISO Page 8 Once the software installation is complete, the port must be configured for ‘ RTS Enable ’. This is accomplished by using the Device Manager in Windows 9X, ME, and Windows 2000. The port that the OMG-CONV-485-ISO is attached must be selected under Ports (COM &...

Installation OMG-CONV-485-ISO Page 9 System Installation The OMG-CONV-485-ISO can be connected to any existing RS-232 port. A cable such as the CA-177 can 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-IS...

Technical Description OMG-CONV-485-ISO Page 10 Technical Description The OMG-CONV-485-ISO converts an existing RS-232 serial port into a field selectable RS-422/485 port for industrial automation and control applications. Connector Pin Assignments RS-232 Signals (DB-25 Female) Signal Name Pin # Mode...

Specifications OMG-CONV-485-ISO Page 11 Specifications Environmental Specifications Specification Operating Storage Temperature Range 0º to 50º C (32º to 122º F) -20º to 70º C (-4º to 158º F) Humidity Range 10 to 90% R.H. Non-Condensing 10 to 90% R.H. Non-Condensing Manufacturing • All Printed Circu...

Appendix A - Troubleshooting OMG-CONV-485-ISO Page 12 Appendix A - Troubleshooting Serial Utility test software is supplied wit h the adapter and will be used in the troubleshooting procedures. By using this software and following these simple steps, most common problems can be eliminated without th...

Appendix B - How To Get Assistance OMG-CONV-485-ISO Page 13 Appendix B - How To Get Assistance Please refer to Appendix A - Troubleshooting prior to calling Technical Support. 1. Read this manual thoroughly before attempting to install the adapter in your system. 2. When calling for technical assist...

Appendix C – Electrical Interface OMG-CONV-485-ISO Page 14 Appendix C - Electrical Interface RS-232 Quite possibly the most widely used communication standard is RS-232. This implementation has been defined and revised several times and is often referred to as RS-232 or EIA/TIA -232. The IBM PC comp...

Appendix C – Electrical Interface OMG-CONV-485-ISO Page 15 RS-485 RS-485 is backwardly compatible with RS-422; however, it is optimized for partyline or multi-drop applications. The output of the RS-422/485 driver is capable of being Active (enabled) or Tri-State (disabled). This capability allows m...

Appendix D – Ground Loop Phenomenon OMG-CONV-485-ISO Page 16 Appendix D - Ground Loop Phenomenon What is Ground Loop? Ground loop Phenomenon occurs when two (or more) pieces of equipment are connected together with a common ground and a different ground potential exists at each location. This curren...

Appendix E - Asynchronous Communications OMG-CONV-485-ISO Page 17 Appendix E - Asynchronous Communications Serial data communications implies that individual bits of a character are transmitted consecutively to a receiver that assembles the bits back into a character. Data rate, error checking, hand...

Appendix G - Compliance Notices OMG-CONV-485-ISO Page 19 Appendix G - Compliance Notices Federal Communications Commission Statement FCC - This equipment has been tested and found to comply with the limits for Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to...

WARRANTY/ DISCLAIMER OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for aperiod of 13 months from date of purchase. OMEGA’s WARRANTY adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping...