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RTS and Auto Transceiver Control

 
In RS485 communications the driver must be enabled and disabled as needed, allowing all 
cards to share a two wire cable. This card provides automatic control, where the driver is 
enabled when data is ready to be transmitted. The driver remains enabled for the transmission 
time of one additional character after data transfer is complete and then is disabled. The cards 
automatically adjust their timing to the baud rate of the data. 
  
The receiver is also normally disabled during RS485 transmissions. 

 

CE Mark

  
If your card is CE-marked, it meets the requirements of EN50081-1:1992 (Emissions), 
EN50082-1:1992 (Immunity), and EN60950:1992 (Safety). 

Содержание PCI-422/485-2

Страница 1: ...cess underutilized and idle equipment along with credit for buybacks and trade ins Custom engineering so your equipment works exactly as you specify Critical and expedited services Leasing Rentals Demos In stock Ready to ship TAR certified secure asset solutions Expert team I Trust guarantee I 100 satisfaction All trademarks brand names and brands appearing herein are the property of their respect...

Страница 2: ...10623 Roselle Street San Diego CA 92121 858 550 9559 FAX 858 550 7322 contactus accesio com www accesio com MODEL PCI 422 485 2 USER MANUAL FILE MPCI 422 485 2 A1b ...

Страница 3: ...rights of others IBM PC PC XT and PC AT are registered trademarks of the International Business Machines Corporation Printed in USA Copyright 2000 2005 by ACCES I O Products Inc 10623 Roselle Street San Diego CA 92121 All rights reserved WARNING ALWAYS CONNECT AND DISCONNECT YOUR FIELD CABLING WITH THE COMPUTER POWER OFF ALWAYS TURN COMPUTER POWER OFF BEFORE INSTALLING A CARD CONNECTING AND DISCON...

Страница 4: ... excluded by warranty Warranty commences with equipment shipment Following Years Throughout your equipment s lifetime ACCES stands ready to provide on site or in plant service at reasonable rates similar to those of other manufacturers in the industry Equipment Not Manufactured by ACCES Equipment provided but not manufactured by ACCES is warranted and will be repaired according to the terms and co...

Страница 5: ...dows NT 4 and Lower Without PCIFind EXE 12 Figure 3 1 Option Selection Map 13 Chapter 4 Address Selection 14 Chapter 5 Programming 15 Sample Programs 15 Windows Programming 15 Initialization 15 Table 5 1 Baud Rate Divisors 16 Reception 17 Transmission 17 Chapter 6 Connector Pin Assignments 19 Table 6 1 Connector Pin Assignments 19 Appendix A Application Considerations 20 Balanced Differential Sign...

Страница 6: ...rt these options by means of jumpers on the card See the Option Selection section of this manual for more details COM Port Compatibility Type 16550 UARTs are used as the Asynchronous Communication Element ACE These include a 16 byte transmit receive FIFO buffer to protect against lost data in multitasking operating systems while maintaining 100 compatibility with the original IBM serial port PCI b...

Страница 7: ...ready to be transmitted The driver remains enabled for the transmission time of one additional character after data transfer is complete and then is disabled The cards automatically adjust their timing to the baud rate of the data The receiver is also normally disabled during RS485 transmissions CE Mark If your card is CE marked it meets the requirements of EN50081 1 1992 Emissions EN50082 1 1992 ...

Страница 8: ...t enables or disables the interrupts and the card will not communicate if the bit is pulled high Differential Communication Mode Multipoint Compatible with RS422 and RS485 specifications Up to 32 drivers and receivers allowed on line Serial communications ACE used is type 16550 Driver Receivers used are type 75176 Receiver Input Sensitivity 200 mV differential input Common Mode Rejection 12V to 7V...

Страница 9: ...TRANSCEIVER AUTO RTS CIRCUITRY OSCILLATOR PCI INTERFACE CHIP UART 16550 OR SIMILAR CO MPUTER PCI BUS DB9M Tx Rx Tx Rx RS485 MODE ONLY Tx Rx IRQ TYPICAL OF 2 Figure 1 1 Block Diagram ...

Страница 10: ...ce the CD into your CD ROM drive 2 Type B to change the active drive to the CD ROM drive 3 Type GLQR JJ to run the install program 4 Follow the on screen prompts to install the software for this board WINDOWS 1 Place the CD into your CD ROM drive 2 The system should automatically run the install program If the install program does not run promptly click START RUN and type B GLQR JJ click OK or pre...

Страница 11: ...ess and IRQ assigned to installed PCI devices In Windows the Windows sample programs demonstrate querying the registry entries created by PCIFind and NTIOPCI SYS during boot up to determine this same information Windows COM Numbers Under Windows 9x the card will typically install as COM5 and COM6 Using Device Manager these assignments can be changed to any available COM number greater than COM4 li...

Страница 12: ...stic impedance Installing a jumper at the location labeled LDO applies a 120Ω load across the output for RS 422 mode and across the transmit receive input output for RS 485 operation Installing a jumper at the location labeled LDI applies a 120Ω load across the input for RS 422 operation The card provides biasing for the RS 485 mode CLK X1 and CLK X4 Placement of this jumper controls baud rate CLK...

Страница 13: ...on board processor Each port of a multiport card has a separate subkey under the CurrentControlSet Services Serial subkey in the registry In each of these subkeys you must add values for DosDevices Interrupt InterruptStatus PortAddress and PortIndex because these are not detected by the Hardware Recognizer For descriptions and ranges for these values see Regentry hlp the Registry help file on the ...

Страница 14: ...tion Map Jumpers RS422 Select differential RS 422 four wire communications mode RS485 A RS485 B Select differential RS 485 two wire communications mode LDO Apply load to RS 422 output or RS 485 LDI Apply load to RS 422 input X1 X4 Select either 115 2 Kbaud or 460 8 Kbaud maximum ...

Страница 15: ...pective IRQs and DMAs if any allotted Alternatively some operating systems Windows 95 98 2000 can be queried to determine which resources were assigned In these operating systems you can use either PCIFind or the Device Manager utility from the System Properties Applet of the control panel These cards are installed in the Data Acquisition class of the Device Manager list Selecting the card then cl...

Страница 16: ...fferent The remainder of this chapter describes DOS programming Initialization Initializing the chip requires knowledge of the UART s register set The first step is to set the baud rate divisor You do this by first setting the DLAB Divisor Latch Access Bit high This bit is Bit 7 at Base Address 3 In C code the call would be outportb BASEADDR 3 0x80 You then load the divisor into Base Address 0 low...

Страница 17: ...ired word length Bit 2 determines the number of stop bits There can be either one or two stop bits If Bit 2 is set to 0 there will be one stop bit If Bit 2 is set to 1 there will be two stop bits Bits 3 through 6 control parity and break enable They are not commonly used for communications and should be set to zeroes Bit 7 is the DLAB discussed earlier It must be set to zero after the divisor is l...

Страница 18: ...If the interrupt is for Received Data Available the handler then reads the data If no interrupt is pending control exits the routine A sample handler written in C is as follows readback inportb BASEADDR 2 if readback 4 Readback will be set to 4 if data are available data i inportb BASEADDR outportb 0x20 0x20 Write EOI to 8259 Interrupt Controller return Transmission The Auto feature of the PCI 422...

Страница 19: ...o send while inportb BASEADDR 5 0x20 Wait until transmitter is empty outportb BASEADDR data i i outportb BASEADDR 4 inportb BASEADDR 4 0xFD Reset RTS bit without altering states of other bits Caution The OUT2 bit of the UART must be set low for proper interrupt driven communication This bit enables or disables the interrupts and the card will not communicate if the bit is pulled high ...

Страница 20: ...2 Functions RS485 Functions 1 Rx Receive Data 2 Tx Transmit Data TRx Transmit Receive Data 3 Tx Transmit Data TRx Transmit Receive Data 4 5 GND Ground GND Ground 6 7 8 9 Rx Receive Data Table 6 1 Connector Pin Assignments Note If connections are to be made to a CE marked version then CE certifiable cabling and breakout methodology Cable shields connected to ground at the mounting bracket shielded ...

Страница 21: ...less than 200 mV the receiver will provide the opposite logic state on its output The maximum operating voltage range is from 6V to 6V allowing for voltage attenuation that can occur on long transmission cables A maximum common mode voltage rating of 7V provides good noise immunity from voltages induced on the twisted pair lines The signal ground line connection is necessary in order to keep the c...

Страница 22: ...As many as 32 driver receiver pairs can share a two wire party line network Many characteristics of the drivers and receivers are the same as in the RS422 Standard One difference is that the common mode voltage limit is extended and is 12V to 7V Since any driver can be disconnected or tristated from the line it must withstand this common mode voltage range while in the tristate condition RS485 Two...

Страница 23: ...e a master node and all others be slaves The network is connected so that the master communicates to all slaves and all slaves communicate only with the master This has advantages in equipment that uses mixed protocol communications Since the slave nodes never listen to another slave s response to the master a slave node cannot reply incorrectly ...

Страница 24: ...ust want to give us some feedback please email us at manuals accesio com Please detail any errors you find and include your mailing address so that we can send you any manual updates 10623 Roselle Street San Diego CA 92121 Tel 858 550 9559 FAX 858 550 7322 www accesio com ...

Страница 25: ...quipment Have surplus equipment taking up shelf space We ll give it a new home Learn more Visit us at artisantg com for more info on price quotes drivers technical specifications manuals and documentation Artisan Scientific Corporation dba Artisan Technology Group is not an affiliate representative or authorized distributor for any manufacturer listed herein We re here to make your life easier How...

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