Omega Engineering RS-422/485 manual

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Contents I NTRODUCTION ..........................................................................1 O VERVIEW ................................................................................................ 1 W HAT ’ S I NCLUDED ................................................................................ 1 F ACTORY D EFAULT S ETTINGS .........[...]

A PPENDIX A - T ROUBLESHOOTING .........................................19 A PPENDIX B - H OW T O G ET A SSISTANCE E RROR ! B OOKMARK NOT DEFINED . A PPENDIX C - E LECTRICAL I NTERFACE ...................................22 RS - 422 ..................................................................................................... 22 RS - 485 ....[...]

Introduction OMG - ULTRA - COMM422 Page 1 Introduction Overview The OMG - ULTRA - COMM422 provides the PC with four additional RS - 422/485 serial ports for terminals, modems, printers, etc. The unique feature of the OMG - ULTRA - COM M422 is the ability to be RS - 485 compatible without the need for special software or drivers. This ability is esp[...]

Card Setup OMG - ULTRA - COMM422 Page 2 Card Setup The OMG - ULTRA - C OMM422 contains several jumper straps, which must be set for proper operation. Address Selection Each port on the OMG - ULTRA - COMM422 occupies eight consecutive I/O locations. A DIP - switch is used to set the base address for these locations. The OMG - ULTRA - C OMM422 has a [...]

Card Setup OMG - ULTRA - COMM422 Page 3 The second mode of address selection provides the compatibility mode. In this mode the DIP - switch sets the base address and the adapter occupies 32 consecutive I/O locations. The following tabl e illustrates the location of each port and its relationship to the other ports. Note: For switches 1 - 5 to becom[...]

Card Setup OMG - ULTRA - COMM422 Page 4 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 - s[...]

Card Setup OMG - ULTRA - COMM422 Page 5 Interrupt Modes Headers J1A through J4A select the interrupt modes for each port. Each port must be set in the correct mode to insure proper operation. ‘ N ’ indicates the ( N )ormal, single interrupt per port mode. ‘ S ’ Indicates the ( S )hared interru pt mode, which allows more than one port to acc[...]

Card Setup OMG - ULTRA - COMM422 Page 6 RS - 485 Enable Modes RS - 485 is ideal for multi - drop or network environments. RS - 485 requires a tri - state driver (not dual - state) that will allow the electrical presence of the driver to be removed from the line. The driver is in a t ri - state or high impedance condition when this occurs. Only one [...]

Card Setup OMG - ULTRA - COMM422 Page 7 Interface Mode Examples J1D – J4D AT RT NE Figure 6 - Headers J1D - J4D , RS - 422 AT RT NE Figure 7 - Headers J1D - J4D, RS - 485 ‘Auto’ Enabled, with ‘No Echo’ AT RT NE Figure 8 - Headers J1D - J4D, RS - 485 ‘Auto’ Enabled, with ‘Echo’[...]

Card Setup OMG - ULTRA - COMM422 Page 8 Inter face Mode Examples J1D – J4D (continued) AT RT NE Figure 9 - Headers J1D - J4D, RS - 485 ‘RTS’ Enabled, with ‘No Echo’ AT RT NE Figure 10 - Headers J1D - J4D, RS - 485 ‘RTS ’ Enabled, with ‘Echo’[...]

Card Setup OMG - ULTRA - COMM422 Page 9 Line Termination Typically, each end of the RS - 485 bus must have line terminating resistors (RS - 422 terminates at the receive end only). A 120 - ohm resistor is across each RS - 530/422/485 input in addition to a 1K ohm pull - up/pull - do wn combination that bias the receiver inputs. Headers J1E through [...]

Card Setup OMG - ULTRA - COMM422 Page 10 Clock Modes The OMG - ULTRA - COMM422 employs a unique clocking option that allows the end user to select from divide by 4, divide by 2 and divide by 1 clocking modes. These modes are selected at Headers J1C through J4C. To select the Baud rates commonly associated with COM: ports (i.e. 2400, 4800, 9600, 19.[...]

Card Setup OMG - ULTRA - COMM422 Page 11 Baud Rates and Divisors for the ‘Div1’ mode The following table shows some common data rates and the rates you should choose to match them if using the adapter in the ‘Div1’ mode. For this Data Rate Choose this Data Rate 1200 bps 3 00 bps 2400 bps 600 bps 4800 bps 1200 bps 9600 bps 2400 bps 19.2K bps[...]

Card Setup OMG - ULTRA - COMM422 Page 12 Baud Rates and Divisors for t he ‘Div2’ mode The following table shows some common data rates and the rates you should choose to match them if using the adapter in the ‘Div2’ mode. For this Data Rate Choose this Data Rate 1200 bps 600 bps 2400 bps 1200 bps 4800 bps 2400bps 9600 bp s 4800 bps 19.2K bp[...]

Installation OMG - ULTRA - COMM422 Page 13 Installation The OMG - ULTRA - COMM422 can be installed in any of the PC expansion slots. The OMG - ULTRA - COMM422 contains several jumper straps for each port that must be set for proper operation. 1. Turn off PC power. Disconnect the power cord. 2. Remove the PC case cover. 3. Locate an available slot a[...]

Technical Description OMG - ULTRA - COMM422 Page 14 Technical Description The OMG - ULTRA - COMM422 utilizes the 16550 UAR T. This chip features programmable baud rates, data format, interrupt control and a 16 - byte input and output FIFO. Also available as options are the Startech 16C650 and the Texas Instruments 16C750 UARTs, that provide deeper [...]

Technical Description OMG - ULTRA - COMM422 Page 15 Interrupts A good description of an interrupt and it’s importance to the IBM PC can be found in the book ‘Peter Norton’s In side the PC, Premier Edition’: “ One of the key things that makes a computer different from any other kind of man - made machine is that computers have the capabili[...]

Technical Description OMG - ULTRA - COMM422 Page 16 Why use an ISP? The answer to the polling inefficiency was the I nterrupt S tatus P ort (ISP). The ISP is a read only 8 - bit register that sets a corresponding bit when an interrupt is pending. Port 1 interrupt line corresponds with Bit D0 of the status port, Port 2 with D1 etc. The use of this p[...]

Technical Description OMG - ULTRA - COMM422 Page 17 Connector Pin Assignments DB - 9 Pin Assignments Signal Name Pin # Mode GND Ground 5 TX + Transmit Data Positive 4 Output TX - Transmit Data Negative 3 Output RTS+ Request To Send Positive 6 Output RTS - Request To Send Negative 7 Output RX+ Receive Data Positive 1 Input RX - Receive Data Negative[...]

Specifications OMG - ULTRA - COMM422 Page 18 Spec ifications 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 • IPC 610 - A Class - III standards are adhered[...]

Appendix A - Troubleshooting OMG - ULTRA - COMM422 Page 19 Appendix A - Troubleshooting A Serial Utility Diskette is supplied with the adapter and will be used in the troubleshooting procedures. By using this diskette an d following these simple steps, most common problems can be eliminated without the need to call Technical Support. 1. Identify al[...]

Appendix A - Troubleshooting OMG - ULTRA - COMM422 Page 20 8. The following are known I/O conflicts: • The 278 and 378 settings may conflict with your printer I/O adapter. • 3B0 cannot be u sed if a Monochrome adapter is installed. • 3F8 - 3FF is typically reserved for COM1: • 2F8 - 2FF is typically reserved for COM2: • 3E8 - 3EF is typic[...]

OMG - ULTRA - COMM422 Page 21 Appendix B - How To Get Assistance Please refer to Troubleshooting Guide prior to calling Technical Support. 1. Begin by reading through the Trouble Shooting Guide in Appendix A. If assistance is still needed please see below. 2. When calling for technical assistance, please have your user manual and current adapter se[...]

Appendix C - Electrical Interface OMG - ULTRA - COMM422 Page 22 Appendix C - Electrical Interface RS - 422 The RS - 422 specification defin es the electrical characteristics of balanced voltage digital interface circuits. RS - 422 is a differential interface that defines voltage levels and driver/receiver electrical specifications. On a differentia[...]

Appendix D - Asynchronous Communications OMG - ULTRA - COMM422 Page 23 Appendix D - 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 r ate, error checking, handshaking, and character framing (start/stop b[...]

Appendix E - Silk - Screen OMG - ULTRA - COMM422 Page 24 Appendix E - Silk - Screen 4.2" 8.0" 3.9"[...]

Appendix F - Compliance Notices OMG - ULTRA - COMM422 Page 25 Appendix F - Compliance Notices Federal Communications Commission Statement FCC - This equipment has b een 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 provide reasonable protection against harmf[...]

W ARRANTY / DISCLAIMER OME GA ENGINEERING, INC. war rants this unit to be free of defects in materials and workmanship for a period of 1 3 months from date of purc hase. OM E G A ’ s W ARRAN TY adds an additional one (1) month grace period to the normal one (1) year pr oduct warranty to cover handling and shipping time. This ensures that OME GA ?[...]

M 3 184 /0303 Where Do I Find Ever ything I Need for Pr ocess Measurement and Control? OM EGA…Of Course! Shop online at www .omega.com TEMPERA TURE   Thermocouple, RTD & Thermistor Probes, Connectors, Panels & Assemblies   Wire: Thermocouple, RTD & Thermistor   Calibrators & Ice Point References   Recorders[...]