======================SERIAL_PROTOCALS======================================= V.32bis synchs/asynch,full dupx,2wires,4.8K,7.2K,9.6K,12K,14.4Kbps Line drivers and receivers used to exchange data between nodes on a network a transmission line if rise and/or fall time greater than half time for signal to travel from the transmitter to receiver. EIA Electronics Industry Association produced standards for RS485, RS422, RS232, and RS423 previously marked with prefix "RS" to indicate recommended standard; RS232 (single-ended) introduced in 1962, allows for up to 20K bits/second to 50Ft. @ Independent channels for two-way (full-duplex) idle state (MARK) signal negative to common, active state (SPACE) signal positive to common. RS422 (differential) pair of converters from RS232 to RS422 (and back again) can be used to form "RS232 extension cord." up to 100K bits/second up to 4000 Ft. also specified for multi-drop (party-line) a "bus" of up to 10 receivers. Quasi multi-drop networks (4-wire) constructed using RS422 devices.in half-duplex mode, single master sends to one "slave" Typically one device (node) addressed by host a response is received from that device. 4-wire, half-duplex constructed to avoid "data collision" RS485 up to 32 drivers and 32 receivers on a single (2-wire) bus. introduction of "automatic" repeaters and high-impedance drivers / receivers can be extended to hundreds (or even thousands) of nodes both drivers and receivers in the "tri-state" mode drivers are able to withstand "data collisions" hardware units (converters, repeaters, micro-processor controls) remain in receive mode until ready to transmit Single master systems initiates a communications request to "slave node" by addressing that unit. hardware detects start-bit of transmission and automatically enables (on the fly) RS485 transmitter Once character sent reverts back to receive mode in about 1-2 microseconds transmitter will automatically re-trigger with each new character Once a "slave" unit is addressed able to respond immediately because of the fast transmitter turn-off time of the automatic device. utilize bandwidth with up to 100% through put. SPECIFICATIONS RS232 RS423 RS422 RS485 Mode of Operation SINGLE SINGLE DIFFER- DIFFER- ENDED -ENDED ENTIAL ENTIAL Number Drivers and 1 DRIVER 1 DRIVER 1 DRIVER 1 DRIVER Receivers One Line 1 RECVR 10 RECVR 10 RECVR 32 RECVR Maximum Cable Length 50 FT. 4000 FT. 4000 FT. 4000 FT. Maximum Data Rate 20kb/s 100kb/s 10Mb/s 10Mb/s Max Driver Output -0.25V to Voltage +/-25V +/-6V +6V -7V to +12V Driver Out Loaded +/-5V to +/-3.6V +/-2.0V +/-1.5V (Loaded Min.) +/-15V Driver Unloaded +/-25V +/-6V +/-6V +/-6V Driver Load Imped 3k to 7k >=450 100 54 IoutHigh Z Pwr On N/A N/A N/A +/-100uA IoutHigh Z Pwr Off +/-6mA @ +/-100uA +/-100uA +/-100uA State +/-2v Slew Rate (Max.) 30V/uS Adjustable N/A N/A Rec Input Range +/-15V +/-12V -10V to -7V to +12V 10V Receiver Sens +/-3V +/-200mV +/-200mV +/-200mV Receiver Res 3k to 7k 4k min. 4k min. >=12k start bit requires gate senses falling edge during clock high. stop bit set to detect a rising edge. Usually customer has option of setting the lower 3 address bits externally. But this requires pins. ViH_min = 3V ViL_max = 1.5 at 5VCC min low time = 4.17uS min high time is 4us start data high = bus free max bus cap 400pf = 100kbits/sec less tan 10k ohms http://wombat.doc.ic.ac.uk/foldoc/index.html flow control stop sending data When buffer at "high water mark" resume at "low water mark" escape sequence ("escape code") (ASCII 27) from DEC vt100 video terminal perform special function , Hayes modem uses "+++" Device Control four ASCII characters, DC1, DC2, DC3, and DC4, once used to remotely control equipment paired,DC1/DC3 turning one device on/off,DC2/DC4 another null modem RS-232 cable, for two computers directly both computers transmit pin three and recieve pin two, It also needs male connectors at both ends to spec . Give me a break! the canonical humorous response is "Control C". SOH Null ASCII_0 SOH Start Of Header ASCII_1 STX Start Of Text ASCII_2 ETX End Of Text ASCII_3 control-C Unix_interrupt EOT End Of Transmis ASCII_4 ENQ ENQuire. ASCII_5 ACK ACKnowledge ASCII_6 BEL sound bell ASCII_7 BS Backspace ASCII_8 HT tab ASCII_9 Control-I Unix => "\t" LF line feed ASCII_10 control-J Unix => "\n" VT Vertical Tab ASCII_11 FF form feed ASCII_12 Control-L CR CursReturn2Left ASCII_13 Control-M Unix => "\r" SO ShiftOut AltChars ASCII_14 Control-N SI ShiftIn AltChars ASCII_15 Control-O DLE Data Link Escape ASCII_16 DC1 resume output ASCII_17 control-Q XON DeviceControl1 DC2 DeviceControl2 ASCII_18 DC3 suspend output ASCII_19 control-S XOFF DeviceControl3 DC4 DeviceControl4 ASCII_20 NAK Neg Acknowledge ASCII_21 SYN Synchronous idle ASCII_22 ETB End Transm Block ASCII_23 CAN Cancel ASCII_24 Control-X EM End of Medium ASCII_25 SUB Substitute ASCII_26 ESC escape ASCII_27 ESCAPE FS File Separator ASCII_28 GS Group Separator ASCII_29 RS Record Separator ASCII_30 US Unit Separator ASCII_31 ASCII American Standard Code for Information Interchange US-ASCII uses lower seven bits (character points 0 to 127) D-type connector so named because one side is shorter (with one less pin) (squarish) "D" shape.25-way(13+12 pins) a9-way(5+4 pins) UART Universal Asynchronous Receiver/Transmitter a transmitter (parallel-to-serial converter) a receiver each clocked separately. parallel side of a UART isconnected to bus of computer. computer writes to UART's transmit data register (TDR), UART start transmit on the serial line. UART's status register flag bit if ready for another byte. Another status register bit says UART has received a byte computer read it from receive data register (RDR). If another byte received before previous one read, UART signal an "overrun" error via another status bit. The UART set up to interrupt the computer format the UART by the UART's control register incorrectly formated signal "framing/"parity error". Often the clock will run at 16 times the baud rate to read each bit in middle of its allotted time period makes the UART more tolerant to "jitter" stop bit extra "1" bits which follow the data and any parity bit. mark end of a byte or character). start bit signals the start of transmission oon a serial line zero-one transition tells receiver when to start sampling the signal to extract the data bits. synchronous Two or more processes common timing signals. asynchronous Not synchronised by shared clock , execution independently loser An unexpectedly bad situation, program,programmer Someone who habitually loses. (Even winners can lose ) Someone who knows not and knows not that he knows not. Emphatic forms real loser,total loser,complete loser" (not "moby loser", which is a contradiction in terms). RS-232C The EIA RS-232C electrical signal unbalanced +/- 5 to +/- 12V, polar non return to zero speeds up to 19.2 kilobits per second. DTE Data Terminal Equipment controls communication channel (terminals, computers) DCE Data Communication Equipment ...typically a modem IF "straight-through" cable (p1 to p1, p2 to p2 etc.) DTE should a male connector + trans on p3 and rece p2. gender mender gender bender,gender blender,sex changer,homosexualadaptor two male/female connectors used to correct mismatch RS-232 Originally DCE was modem and DTE was computer/terminal DCE RS-232 have female connector and tran p2 and rec p3 DTE RS-232 have male connector and tran p3 and rec p2 http://wombat.doc.ic.ac.uk/foldoc/ foldoc.cgi?hardware+handshaking TX ____ ____ TX | | RV ___/|\__| __ RV |_____| GND _____________ GND DTE DCE DTE: Data Terminal Equipment (terminal) DCE: Data Circuit-terminating Equipment (modem,computer) RS232C Max 20Kbps @ 15meters unbalanced Logic_0 "space" Vout +3V -> +15B Logic_1 "mark" Vout -3V -> -15V RS422 twisted pair balanced 10Mbps @ 12 meters .1Mbps@1.2Km _ ___ _______ ___ _________ | ST| D0| D1| D2 D2| D4 D5 D6| D7| P | SB| : |___| |___| |___________| |___| | LSB MSB startBit ST data D ParityBit P StopBit 1 T 1/Baud 9600Baud= 104.2us Software Handshake XON and XOFF Hardware DTE DCE TX ____ ____ TX | | RV ___/|\__| __ RV |_____| RTS ___ ____ RTS | | CTS___/|\__| __ CTS |_____| GND _____________ GND RTS: Request to send CTS: Clear to send DTR: Data terminalready compu sets space_Hi so printer recev DSR: Data set ready printer sets space_Hi to receive DCD: Data carrier detect must space_Hi for printer to receiv Hardware DTE DCE TX ____ ____ TX | | RV ___/|\__| __ RV |_____| RTS ___ ____ RTS ??????????? | | CTS___/|\__| __ CTS |_____| DTR ___ ____ DTR | | DSR___/|\__| __ DSR |_____| GND _____________ GND RTS: Request to send CTS: Clear to send DTR: Data terminalready DSR: Data set ready TXD: Transmit data RXD: Receive data RTS: Request to send (Pc sets this when ready to send ) CTS: Clear to send (modem ready to transmit ) DTR: Data terminalready (PC tells modem ready to send ) DSR: Data set ready (modem tells PC ready to transmit) CD: Carrier detect (modem sets this when detects PC) DTE: Data Terminal Equipment (terminal) DCE: Data Circuit-terminating Equipment (modem,computer) Half_dulplex data sent only in one direction at a time Full_dulplex data sent in both directions at a time Synchronous transmit data in blocks using sync characters 1baud one audio signal transitions per second FSK: Frequency_shift_Keying logic_0 = 1080Hz Logic_1 = 1750Hz 1baud =1bps PSK: Phase_shift_Keying logic_1/0 set by alternating carrier phase more bits per baud since phases are 0,90,180,270 QAM: Quadrature)_amplitude_modulation Both phase and frequency 1.7KHz or1.8Khz @ 2400baud only 4 bits usable per baud TCM: TCQAM or Trellic_coded quadrature_amplitude_modulation 6bits per baud. 14,400 bps modems use this CCITT V.XX Standards Consultative Committee InternalTelepho&Telegraph V.22 synch/asynch ,full duplex,2 wires, 1200bpsdata V.22bis synch/asynch ,full duplex,2 wires, 2400/1200bpsdata V.32 synch/asynch ,full duplex,2 wires, 9600bpsdata V.32bis synchs/asynch,full dupx,2wires,4.8K,7.2K,9.6K,12K,14.4Kbps V.34bis synchs/asynch,full dupx,2wires,28.8Kbps,speed<=line noise V.35 synchs/asynch ,full duplex,2 wires Bell stand : 0.3K,1.2K,2.4K,4.8Kbps TXD: Transmit data RXD: Receive data RTS: Request to send (Pc sets high when ready to send ) CTS: Clear to send (modem ready to transmit ) DTR: Data terminalready (PC tells modem ready to send ) DSR: Data set ready (modem tells PC ready to transmit) CD: Carrier detect (modem sets this when detects PC) DTE: Data Terminal Equipment (terminal) DCE: Data Circuit-terminating Equipment (modem,computer) NUL Null DLE Data Link Escape SOH StartHeading DC1 Device Control 1 STX Start Text DC2 Device Control 2 ETX End Text DC3 Device Control 3 EOT End Trans DC4 Device Control 4 ENQ Enquiry EM End of Medium ACK Acknowledge SUB Substitute BEL Bell ESC Escape BS BackSpace FS File Separator HT Horizontal Tab GS Group Separator LF Line Feed RS Recorder Separator VT Vertical Tab US Unit Separator FF Form Feed DEL Delete CR Carriage Return SO Shift Out SI Shift In NAK Negative Ackno SYN Synch s Idle ETB End Trans Block CAN Cancel Hex Dec Char Hex Dec Char Hex Dec Char Hex Dec Char 00 00 NUL 20 32 space 40 64 @ 60 96 ` 01 01 SOH 21 33 ! 41 65 A 61 97 a 02 02 STX 22 34 " 42 66 B 62 98 b 03 03 ETX 23 35 # 43 67 C 63 99 c 04 04 EOT 24 36 $ 44 68 D 64 100 d 05 05 ENQ 25 37 % 45 69 E 65 101 e 06 06 ACK 26 38 & 46 70 F 66 102 f 07 07 EEL 27 39 ' 47 71 G 67 103 g 08 08 BS 28 40 ) 48 72 H 68 104 h 09 09 HT 29 41 ( 49 73 I 69 105 i GA 10 L 2A 42 * 4A 74 J 6A 106 j OB 11 VT 2B 43 + 4B 75 K 6B 107 k GC 12 FF 2C 44 , 4C 76 L 6C 108 I OD 13 CR 2D 45 - 4D 77 M 60 109 m GE 14 SO 2E 46 . 4E 78 N 6E 110 n OF 15 SI 2F 47 / 4F 79 O 6F 111 o 10 16 DLE 30 48 0 50 80 P 70 112 p 11 17 DC1 31 49 1 51 81 Q 71 113 q 12 18 DC2 32 50 2 52 82 R 72 114 r 13 19 DC3 33 51 3 53 83 S 73 115 s 14 20 DC4 34 52 4 54 84 T 74 116 t 15 21 NAK 35 53 5 55 85 U 75 117 u 16 22 SYN 36 54 6 56 86 V 76 118 v 17 23 ETB 37 55 7 57 87 W 77 119 w 18 24 CAN 38 56 8 58 88 X 78 120 x 19 25 EM 39 57 9 59 89 Y 79 121 y 1A 26 SUB 3A 58 : 5A 90 Z 7A 122 z 1E 27 ESC 3B 59 ; 5B 91 [ 7B 123 { 1C 28 FS 3C 60 < 5C 92 \ 7C 124 | 1D 29 GS 3D 61 = 5D 93 ] 70 125 } 1E 30 RS 3E 62 > 5E 94 ^ 7E 126 ~ 1F 31 US 3F 63 ? 5F 95 _ 7F 127 DE -----------------------Mac_Modem_Cable----------------------- ____ ____ / V \ Male / 8 7 4 \ / gnd \ | 9 1gnd 5 | | tx rx | \_ 7 6 _/ |_______| rts cts _________ | | \ \ RS232C DB25 Male |13_| \ \ | ()_) _\ \ |12_|()_)|25 | | ()_) _ | | |11_|()_)|24 | | ()_) _ | | |10_|()_)|23 | | ()_) _ | | | _|()_)|22 | |9()_) _ | | | _|()_)|21 | |8()_) _ | | | _|()_)|20 | Signal Gnd |7()_) _ | | | _|()_)|19 | |6()_) _ | | | _|()_)|18 | CTS |5()_) _ | | | _|()_)|17 | RTS |4()_) _ | | | _|()_)|16 | RXD |3()_) _ | | | _|()_)|15 | TXD |2()_) _ | | | _|()_)|14 | Shield GND |1()_) / / | | / / |___|_/___/ 1)reserse tX RXD 2)rev cts rrts ------------------------------------------------------------- _________ | \ \ RS232C DB25 FeMale | \ \ Shield gnd |1() \ \ | () |14 | TXD |2() | | | () |15 | RXD |3() | | | () |16 | Clear to Send|4() | | | () |17 | Request2 Send|5() | | | () |18 | |6() | | | () |19 | Signal Gnd |7() | | | () |20 | |8() | | | () |21 | |9() | | | () |22 | | () | | |10 () |23 | | () | | |11 () |24 | | () | | |12 () |25 | | () / / |13 / / |_____/___/ ------------------------------------------------------------- _________ | | \ \ RS232C DB9 Male | _| \ \ Signal Gnd |5()_) _\ \ | _|()_)|9 | |4()_) _ | | | _|()_)|8 | Clear to Send Transmit Data|3()_) | | | _|()_)|7 | Request to Send Receive Data |2()_) _ | | | _|()_)|6 | |1()_) / / | | / / |___|_/___/ -----------------------PC_Cable----------------------- _________ | | \ \ RS232C DB25 Male |13_| \ \ | ()_) _\ \ |12_|()_)|25 | | ()_) _ | | |11_|()_)|24 | | ()_) _ | | |10_|()_)|23 | | ()_) _ | | | _|()_)|22 | Ring Indicator |9()_) _ | | | _|()_)|21 | CD |8()_) _ | | | _|()_)|20 | DTE Signal Gnd |7()_) _ | | | _|()_)|19 | DSR |6()_) _ | | | _|()_)|18 | CTS |5()_) _ | | | _|()_)|17 | RTS |4()_) _ | | | _|()_)|16 | RXD |3()_) _ | | | _|()_)|15 | TXD |2()_) _ | | | _|()_)|14 | Shield GND |1()_) / / | | / / |___|_/___/ ------------------------------------------------------------- ________ | \ \ RS232C DB9 FeMale | \ \ CD |1() \ \ | ()6 | | DSR RXD |2() | | | ()7 | | RTS TXD |3() | | | ()8 | | CTS DTR |4() | | | ()9 | | Ring Indicator Signal Gnd |5() / / | / / |_____/__/ TXD:Transmit data RXD:Receive data RTS:Request to send (Pc sets this when ready to send ) CTS:Clear to send (modem ready to transmit ) DTR:Data terminalready (PC tells modem ready to send ) DSR:Data set ready (modem tells PC ready to transmit) CD:Carrier detect (modem sets this when detects PC) DTE:Data Terminal Equipment (terminal) DCE:Data Circuit-terminating Equipment (modem,computer) -----------------------Gender_Change----------------------- ________ | \ \ RS232C DB9 FeMale | \ \ CD |1() \ \ | ()6 | | DSR RXD |2() | | | ()7 | | RTS TXD |3() | | | ()8 | | CTS DTR |4() | | | ()9 | | Ring Indicator Signal Gnd |5() / / | / / |_____/__/ ________ | \ \ RS232C DB9 FeMale | \ \ CD |1() \ \ | ()6 | | DSR RXD |2() | | | ()7 | | RTS TXD |3() | | | ()8 | | CTS DTR |4() | | | ()9 | | Ring Indicator Signal Gnd |5() / / | / / |_____/__/ -----------------------COPS----------------------- ________ | \ \ RS232C DB9 FeMale port | \ \ |1() \ \ | ()6 | | RXD |2() | | | ()7 | | RTS TXD |3() | | | ()8 | | CTS |4() | | | ()9 | | Signal Gnd |5() / / | / / |_____/__/ -----------------------CABLE_COPS----------------------- ________ | \ \ RS232C DB9 FeMale | \ \ CD |1() \ \ | ()6 | | DSR RXD |2() | | | ()7 | | RTS TXD |3() | | | ()8 | | CTS DTR |4() | | | ()9 | | Ring Indicator Gnd |5() / / | / / |_____/__/ _________ | | \ \ RS232C DB9 Male | _| \ \ Signal Gnd |5()_) _\ \ | _|()_)|9 | Ring Indicator DTE Rdy |4()_) _ | | | _|()_)|8 | Clear to Send Transmit Data|3()_) | | | _|()_)|7 | Request to Send Receive Data |2()_) _ | | | _|()_)|6 | DCE Ready Receive Line |1()_) / / Signal Detect| | / / |___|_/___/ -----------------------CABLE1_mac----------------------- ________ | \ \ RS232C DB9 FeMale | \ \ |1() \ \ | ()6 | | open |2() | | | ()7 | | |3() | | | ()8 | | |4() | | | ()9 | | |5() / / | / / |_____/__/ ____ ____ / V \ Male / 4 0 8 \ / \ | 5 1,3 9 | | | \_ 6 7 _/ |_______| -----------------------CABLE2_mac----------------------- _________ | | \ \ RS232C DB9 Male | _| \ \ |5()_) _\ \ | _|()_)|9 | |4()_) _ | | | _|()_)|8 | |3()_) | | | _|()_)|7 | |2()_) _ | | | _|()_)|6 | |1()_) / / | | / / |___|_/___/ ____ ____ / V \ Male / 8 7 4 \ / gnd \ | 9 1gnd 5 | | tx rx | \_ 7 6 _/ |_______| rts cts -----------------------Printer_CABLE3----------------------- ____ ____ / V \ Male / 8 7 4 \ / \ | 9 1 5 | | | \_ 7 6 _/ |_______| ____ ____ / V \ Male / 4 7 8 \ / \ | 5 1 9 | | | \_ 6 7 _/ |_______| -----------------------CABLE4----------------------- _________ | | \ \ RS232C DB9 Male | _| \ \ Signal Gnd |5()_) _\ \ | _|()_)|9 | Ring Indicator DTE Rdy |4()_) _ | | | _|()_)|8 | Clear to Send Transmit Data|3()_) | | open | _|()_)|7 | Request to Send Receive Data |2()_) _ | | open | _|()_)|6 | DCE Ready Receive Line |1()_) / / Signal Detect| | / / |___|_/___/ ____ ____ / V \ FeMale / 0 - 5 \ / \ | 7 1 5 | | | \_ 3 2 _/ |_______| -----------------------CABLE5----------------------- Blue Orange Red Yellow ____ ____ / V \ Male / R _ 5 \ / | | \ | O |_| B | | | \_ Y 2 _/ |_______| -----------------------Mac_2_RS232_printer----------------------- _________ | | \ \ RS232C DB25 Male |13_| \ \ | ()_) _\ \ |12_|()_)|25 | | ()_) _ | | |11_|()_)|24 | | ()_) _ | | |10_|()_)|23 | | ()_) _ | | | _|()_)|22 | |9()_) _ | | | _|()_)|21 | |8()_) _ | | Non Reversing | _|()_)|20 | Signal Gnd |7()_) _ | | | _|()_)|19 | DSR =5V |6()_) _ | | | _|()_)|18 | |5()_) _ | | | _|()_)|17 | |4()_) _ | | | _|()_)|16 | Receive Data |3()_) _ | | | _|()_)|15 | Transmit Data|2()_) _ | | | _|()_)|14 | Shield GND |1()_) / / | | / / |___|_/___/ _________ | | \ \ RS232C DB9 Male | _| \ \ TXD |5()_) _\ \ | _|()_)|9 | RXD |4()_) _ | | | _|()_)|8 | GND |3()_) _ | | | _|()_)|7 | Handshake +5V |2()_) _ | | | _|()_)|6 | +12 DTR |1()_) / / | | / / |___|_/___/ Hardware DTE DCE TX ____ ____ TX | | RV ___/|\__| __ RV |_____| RTS ___ ____ RTS | | CTS___/|\__| __ CTS |_____| GND _____________ GND RTS: Request to send CTS: Clear to send DTR: Data terminalready computer sets space_Hi so printer can receive DSR: Data set ready printer sets space_Hi to receive DCD: Data carrier detect must be space_Hi for printer to receive Mac_2_Modem----------------------- _________ | | \ \ RS232C DB9 Male | _| \ \ TXD->RXD |5()_) _\ \ | _|()_)|9 | RXD->TXD |4()_) _ | | | _|()_)|8 | -> p8 GND |3()_) _ | | | _|()_)|7 | -> p7 +5V |2()_) _ | | | _|()_)|6 | +12 -> p8 |1()_) / / | | / / |___|_/___/ _________ | | \ \ RS232C DB9 Male | _| \ \ TXD->RXD |5()_) _\ \ | _|()_)|9 | RXD->TXD |4()_) _ | | | _|()_)|8 | -> p8 GND |3()_) _ | | | _|()_)|7 | -> p7 +5V |2()_) _ | | | _|()_)|6 | +12 -> p8 |1()_) / / | | / / |___|_/___/ RTS: Request to send CTS: Clear to send DTR: Data terminalready computer sets high when ready to transmit DSR: Data set ready modem sets high when ready DCD: Data Carrier detect modem sets high when detect a carrier HX20_2_RS232-------------------------- _________ / _ TXD \ Cable _/ 2()_) _ \ CTS 5()_) _ 4()_) \ RTS _| ()_) _ | RXD 3()_) 6 1()_) | GND \_ DSR _ / DCD 8()_) 7()_) / DTR \________/ T? = Transmit? = DTR H! = Hold! = CTS shorted to RTS _________ | | \ \ RS232C DB9 Male | _| \ \ TXD->RXD |5()_) _\ \ | _|()_)|9 | RXD->TXD |4()_) _ | | | _|()_)|8 | GND |3()_) _ | | | _|()_)|7 | T? -> H! +5V |2()_) _ | | | _|()_)|6 | H! -> T? |1()_) / / | | / / |___|_/___/ TX ____ ____ TX | | RV ___/|\__| __ RV |_____| DTR ____________ DTR RTS ___ | CTS____|________ DCD DCD ___ ____ RTS | | DSR___/|\__| __ DSR |_____| RTS: Request to send CTS: Clear to send DTR: Data terminalready DSR: Data set ready _________ HX20 port / TXD \ HX20_2_RS232 / 2() \ RTS /4() 5()\ CTS | () | GND |1() 6 3()| RXD \ DSR / DTR \ 7() 8() /DCD \____^____/ Request to send RTS: high trans, high or low receive Clear to send CTS: must be high to trans.. norm = don't care Data terminalready DTR: must be high to tramsmit Data set ready DSR: Send out when ready to transmit Data Carrier detect DCD: High all the time HX20 port _________ / _ TXD \ ->p3_d25_RXD _/ 2()_) _ \ CTS->p8_d25_DCD 5()_) _ 4()_) \ RTS ->p8_d25_DCD _| ()_) _ | RXD->p2_d25_TXD 3()_) 6 1()_) | GND ->p7_d25_GND \_ DSR _ / DCD->p6_d25_DSR 8()_) ^ 7()_) /DTR ->p20_d25_DTR \_|______/ CTS shorted to RTS |__ ->p4_d25_RTS _________ CABLE DB25 Male | | \ \ |13_| \ \ | ()_) _\ \ |12_|()_)|25 | | ()_) _ | | |11_|()_)|24 | | ()_) _ | | |10_|()_)|23 | | ()_) _ | | | _|()_)|22 | |9()_) _ | | | _|()_)|21 | DCD |8()_) _ | | | _|()_)|20 | DTR Gnd |7()_) _ | | | _|()_)|19 | DRS |6()_) _ | | | _|()_)|18 | CTS |5()_) _ | | | _|()_)|17 | RTS |4()_) _ | | | _|()_)|16 | RXD |3()_) _ | | | _|()_)|15 | TXD |2()_) _ | | | _|()_)|14 | GND |1()_) / / Shield | | / / |___|_/___/ RS232 TX ____ ____ TX | | RV ___/|\__| __ RV |_____| DTR ____________ DTR RTS ___ | CTS____|________ DCD DCD ___ ____ RTS | | DSR___/|\__| __ DSR |_____| RTS: Request to send CTS: Clear to send DTR: Data terminalready DSR: Data set ready _________ RS232C DB25 Male | | \ \ Clear2 Send2 |13_| \ \ | ()_) _\ \ SignalDetect2|12_|()_)|25 | Test Mode | ()_) _ | | |11_|()_)|24 | DTE source | ()_) _ | | |10_|()_)|23 | Data signal Rate | ()_) _ | | | _|()_)|22 | Ring Indicator |9()_) | | Receive Line | _|()_)|21 | Remote loop back Signal Detect|8()_) _ | | | _|()_)|20 | DTE Rdy (Data Termin ready) Signal Gnd |7()_) _ | | | _|()_)|19 | Request to Send2 Dataset Ready|6()_) | | | _|()_)|18 | Local loop back Clear to Send|5()_) _ | | | _|()_)|17 | DCE source (rec sign timing) Request2 Send|4()_) _ | | | _|()_)|16 | Receive Data2 Receive Data |3()_) | | | _|()_)|15 | DCE source (xtm sign timing) Transmit Data|2()_) _ | | | _|()_)|14 | Transmit Data2 Shield |1()_) / / | | / / |___|_/___/ _________ | | \ \ RS232C DB9 Male | _| \ \ Signal Gnd |5()_) _\ \ | _|()_)|9 | Ring Indicator DTE Rdy |4()_) _ | | | _|()_)|8 | Clear to Send Transmit Data|3()_) | | | _|()_)|7 | Request to Send Receive Data |2()_) _ | | | _|()_)|6 | DCE Ready Receive Line |1()_) / / Signal Detect| | / / |___|_/___/ _________ RS232C DB25 FeMale | \ \ | \ \ Shield |1() \ \ | () |14 | Receive Data2 Receive Data |2() | | | () |15 | DCE source (xtm sign timing) Transmit Data|3() | | | () |16 | Transmit Data2 Clear to Send|4() | | | () |17 | DCE source (rec sign timing) Request2 Send|5() | | | () |18 | Local loop back Dataset Ready|6() | | | () |19 | Clear to Send2 Signal Gnd |7() | | | () |20 | DTE Rdy (Data Termin Equip) Receive Line |8() | | Signal Detect| () |21 | Remote loop back |9() | | | () |22 | Ring Indicator | () | | |10 () |23 | Data signal Rate | () | | |11 () |24 | DTE source SignalDetect2| () | | |12 () |25 | Test Mode Request2Send2| () / / |13 / / |_____/___/ _________ RS232C DB9 Male | | \ \ | _| \ \ Signal Gnd |5()_) _\ \ | _|()_)|9 | Ring Indicator DTE Rdy |4()_) _ | | | _|()_)|8 | Clear to Send Transmit Data|3()_) | | | _|()_)|7 | Request to Send Receive Data |2()_) _ | | | _|()_)|6 | DCE Ready Receive Line |1()_) / / Signal Detect| | / / |___|_/___/ ________ RS232C DB9 FeMale | \ \ | \ \ CD |1() \ \ | ()6 | | DTR TXD |2() | | | ()7 | | CTS RXD |3() | | | ()8 | | RTS DSR |4() | | | ()9 | | Ring Indicator Signal Gnd |5() / / | / / |_____/__/