Omega Engineering RS-422/485 manual Jumper Selections, IRQ Selection

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Card Setup

Jumper Selections

For ease of configuration, the headers are grouped by port. Port one headers have a ‘J1’ prefix; Port two headers have the ‘J2’ prefix, etc. For example, the header that controls the Port one IRQ selection is J1B; the header that controls the Port 2 IRQ selection is J2B. The silk-screen also provides information for configuring the adapter without the use of the manual. This is particularly useful in field re-configuration.

IRQ Selection

Headers J1B through J4B select the interrupt request for each serial port. If COM1: is selected, the corresponding jumper must be on the IRQ4 setting. If COM2: is selected, the corresponding jumper must be on IRQ3.

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Figure 4 – Headers J1B – J4B, IRQ Selection

Note: Most communications software applications default COM3: to IRQ4 and COM4: to IRQ3. This requires the sharing of interrupts between COM1: and COM3:, and between COM2: and COM4:. While this is the default, it is not always the preferred setting. Check your software configuration instructions to determine the most appropriate IRQ selection.

Any two or more ports can share a common IRQ by placing the jumpers on the same IRQ setting and setting the appropriate selections at J1A through J4A. Consult your particular software for IRQ selection. If no interrupt is desired, remove the jumper.

OMG-ULTRA-COMM422

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Contents User’sGuide Canada MexicoBenelux Czech RepublicContents Figures Factory Default Settings IntroductionOverview What’s IncludedAddress Selection Card SetupSwitch Port Switch Settings Address lines à Address Selected Port # Connector Location Address Example Base=2E0Jumper Selections IRQ SelectionJ1A Interrupt ModesRS-485 Enable Modes Interface Mode Examples J1D J4D Headers J1D- J4D, RS-422Headers J1D- J4D, RS-485 ‘RTS’ Enabled, with ‘No Echo’ Line Termination Name FunctionClock Modes DIV4 DIV2For this Data Rate Choose this Divisor Baud Rates and Divisors for the ‘Div1’ modeFor this Data Rate Choose this Data Rate Baud Rates and Divisors for the ‘Div2’ mode Other Operating Systems InstallationOperating System Installation For Windows Users Technical Description FeaturesModem Control Signal Considerations Interrupts Why use an ISP? Connector Pin Assignments DB-9 Pin Assignments DB-37 Connector Pin AssignmentsSignal Name Pin # Mode Port #Specifications Appendix a Troubleshooting OMG-ULTRA-COMM422 Appendix B How To Get Assistance RS-485 Appendix C Electrical InterfaceRS-422 Asynchronous Communications Bit Diagram Appendix D Asynchronous CommunicationsAppendix E Silk-Screen Appendix F Compliance Notices WARRANTY/DISCLAIMER Temperature

RS-422/485 specifications

Omega Engineering is a renowned leader in the field of measurement and control technologies, particularly in the realm of data communication for industrial automation. The RS-422 and RS-485 protocols are part of Omega's robust offering, designed to facilitate reliable and efficient data transmission over relatively long distances. These protocols are widely used in various applications ranging from industrial machinery to building automation systems.

One of the main features of RS-422 is its ability to support long-distance communication, allowing data to be transmitted up to 4,000 feet (approximately 1,200 meters) at speeds of up to 10 Mbps. This is achieved through the use of differential signaling, which provides improved noise immunity compared to single-ended signaling systems. RS-422 employs a single transmitter and multiple receivers, making it ideal for point-to-multipoint configurations.

On the other hand, RS-485 extends the capabilities of RS-422 by allowing multiple devices to be connected on the same bus. It supports up to 32 devices, which can be either transmitters or receivers, making it exceptionally versatile for networking applications. RS-485 can communicate effectively over distances up to 4,000 feet and at speeds of 10 Mbps as well. This makes it an attractive option for applications where several devices need to communicate with a central controller.

An essential characteristic of both protocols is their resilience to electromagnetic interference, which is often a concern in industrial environments. The differential signaling used in RS-422 and RS-485 reduces noise susceptibility, ensuring data integrity even in challenging conditions. Additionally, these protocols function effectively in half-duplex or full-duplex modes, providing flexibility based on application requirements.

Moreover, Omega Engineering’s implementations of RS-422 and RS-485 comply with established standards, ensuring compatibility with a wide range of devices. This interoperability is crucial for seamless integration into existing systems and enhancing overall productivity.

In summary, Omega Engineering's RS-422 and RS-485 technologies offer robust, reliable, and versatile solutions for data communication in industrial settings. With features such as long-distance communication, multiple device connections, and exceptional noise immunity, these protocols continue to serve as foundational technologies in various automation and control applications. As industries evolve, Omega Engineering remains committed to advancing these technologies to meet the growing demands of modern data communication.
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