SDCS-CON-2ASDCS-CON-2A

在串行通信中，傳輸速率常用比特率（每秒傳送的二進(jìn)制位數(shù)）來表示，其單位是比特/秒（bit/s）或bps。傳輸速率是評(píng)價(jià)通信速度的重要指標(biāo)。常用的標(biāo)準(zhǔn)傳輸速率有300、600、1200、2400、4800、9600和19200bps等。不同的串行通信的傳輸速率差別*，有的只有數(shù)百bps，有的可達(dá)100Mbps。

    2．單工通信與雙工通信

串行通信按信息在設(shè)備間的傳送方向又分為單工、雙工兩種方式。

單工通信方式只能沿單一方向發(fā)送或接收數(shù)據(jù)。雙工通信方式的信息可沿兩個(gè)方向傳送，每一個(gè)站既可以發(fā)送數(shù)據(jù)，也可以接收數(shù)據(jù)。

雙工方式又分為全雙工和半雙工兩種方式。數(shù)據(jù)的發(fā)送和接收分別由兩根或兩組不同的數(shù)據(jù)線傳送，通信的雙方都能在同一時(shí)刻接收和發(fā)送信息，這種傳送方式稱為全雙工方式；用同一根線或同一組線接收和發(fā)送數(shù)據(jù)，通信的雙方在同一時(shí)刻只能發(fā)送數(shù)據(jù)或接收數(shù)據(jù)，這種傳送方式稱為半雙工方式。在PLC通信中常采用半雙工和全雙工通信。

3．異步通信與同步通信

    在串行通信中，通信的速率與時(shí)鐘脈沖有關(guān)，接收方和發(fā)送方的傳送速率應(yīng)相同，但是實(shí)際的發(fā)送速率與接收速率之間總是有一些微小的差別，如果不采取一定的措施，在連續(xù)傳送大量的信息時(shí)，將會(huì)因積累誤差造成錯(cuò)位，使接收方收到錯(cuò)誤的信息。為了解決這一問題，需要使發(fā)送和接收同步。按同步方式的不同，可將串行通信分為異步通信和同步通信。

發(fā)送的數(shù)據(jù)字符由一個(gè)起始位、7~8個(gè)數(shù)據(jù)位、l個(gè)奇偶校驗(yàn)位（可以沒有）和停止位（1位、1.5或2位）組成。通信雙方需要對(duì)所采用的信息格式和數(shù)據(jù)的傳輸速率作相同的約定。接收方檢測(cè)到停止位和起始位之間的下降沿后，將它作為接收的起始點(diǎn)，在每一位的中點(diǎn)接收信息。由于一個(gè)字符中包含的位數(shù)不多，即使發(fā)送方和接收方的收發(fā)頻率略有不同，也不會(huì)因兩臺(tái)機(jī)器之間的時(shí)鐘周期的誤差積累而導(dǎo)致錯(cuò)位。異步通信傳送附加的非有效信息較多，它的傳輸效率較低，一般用于低速通信，PLC一般使用異步通信。

同步通信以字節(jié)為單位（一個(gè)字節(jié)由8位二進(jìn)制數(shù)組成），每次傳送l~2個(gè)同步字符、若干個(gè)數(shù)據(jù)字節(jié)和校驗(yàn)字符。同步字符起聯(lián)絡(luò)作用，用它來通知接收方開始接收數(shù)據(jù)。在同步通信中，發(fā)送方和接收方要保持*的同步，這意味著發(fā)送方和接收方應(yīng)使用同一時(shí)鐘脈沖。在近距離通信時(shí)，可以在傳輸線中設(shè)置一根時(shí)鐘信號(hào)線。在遠(yuǎn)距離通信時(shí)，可以在數(shù)據(jù)流中提取出同步信號(hào)，使接收方得到與發(fā)送方*相同的接收時(shí)鐘信號(hào)。由于同步通信方式不需要在每個(gè)數(shù)據(jù)字符中加起始位、停止位和奇偶校驗(yàn)位，只需要在數(shù)據(jù)塊（往往很長）之前加一兩個(gè)同步字符，所以傳輸效率高，但是對(duì)硬件的要求較高，一般用于高速通信。

MURR SWITCH MODE POWER SUPPLY MCS5-230/24 SINGLE PHASE LOT OF 2
 

MOELLER CONTACTOR DIL-1M, VG B DIL 250 LOT OF 2
 

PRESSURE TRANSMITTER?TYPE ZT15 RANGE 0~0.5MPa POWER 24V DC LOT OF 5
 

DWG.NO.331LA06731 NOP OM-2 CHF605/C PH REV C BOARD
 

MITSUBISHI GT15-75TINV BD627B924G52 BOARD
 

TAMAGAWA SEIKI 5PHASE STEPPING MOTOR 2K-S544W
 

PANASONIC AC SERVO DRIVER MADDT1205
 

Vexta Oriental PK569AWM 5 phases stepping motor #1
 

MITSUBISHI MELSEC-Q?POWER SUPPLY UNIT Q64P NNB
 

TOKYO SAWAMURA DENKI?KOGYO DC GEARED MOTOR H11,SS32FJ-GR-36?LOT OF 2 NNB
 

ORIENTAL VEXTA 5-PHASE DRIVER UDK5128NW2
 

KEYENCE POWER &CONTROLLER SJ-B020
 

ORIENTAL MOTOR VEXTA?PK569-NBC 5PH STEPPING MOTOR
 

ORIENTAL MOTOR VEXTA?PK569H-B 5PH STEPPING MOTOR
 

PL PRO-LOG QUADRATURE COUNTER CARD 7318A-04,PWB 117040-002
 

PL PRO-LOG 7314A-05?RS-232-C SCC CARD.PWB 111742-005
 

MITSUBISHI CC-LINK/LT CL2X16-D1C3V
 

YOSHIDA PSD-50V3
 

OMRON SYSMAC CS1W-NC213 POSITION CONTROL?UNIT
 

STEC INC PAC-EC V2.2A
 
HAKKO V606M10 TOUCH?LCD SCREEN GRAPHIC?PANEL,HMI
 

TAKAMURA GEARHEAD REDUCER K6512A
 
YASKAWA VS MINI J7 CIMR-J7AA21P5 1.5KW INVERTER
 

TYLAN NIPPON TYLAN CORP UC FC-780C-HT 20 SCCM O2 MFC MASS FLOW CONTROLLER
 

ABB DSQC 223,YB 560?103-BD/1 BOARD LOT OF 2
 

HY-LOK VALVE P2VH-6T?3000PSI 316 0OQ LOT?OF 4
 

KITZ SCT DIAPHRAGM VALVE PCTFE-SEAT SCV?10K-1/4" KD 316L LOT?OF 2
 
SONY CCD VIDEO CAMERA MODULE XC-ST30 DC10.5-15V
 
SANYO DENKI 103-4507-7046 STEPPING MOTOR LOT OF 6
 
SIEMENS 5SX21(2) 5SM1311-6(2) LOT OF 4
 

FUJI ELECTRIC FA,AUTO BREAKER EA32AC 5A?NEW LOT OF 3
 

MOELLER FAZ-C32-3(3)?FAZ-3-C32(3) LOT OF?6
 

OMRON SOLID STATE RELAY G3PB-245B-VD NEW?NOT IN BOX LOT OF 2
 

MURR MCS10-230/24 SWITCH MODE POWER SUPPLY
 
MITSUBISHI FR-PU04,PARAMETER UNIT LOT OF?3
 

PHOENIX CONTACT POWER SUPPLY QUINT-PS-100-240AC/24DC/10
 

OMRON CS1W-BC083 BASE UNIT TESTED WORKING
 

SIEMENS 6ES7-921-3AA20?-0AA0 CONNECTOR LOT OF 3 NEW
 

TEM TECH LAB MODEL:?HY NV-420M-1/6700-3RANGE: 0~100PSIG NEW
 

NTN BALL SCREW MBSS1540F A06000C5A, STROKE:230mm,PITCH:4mm OVERALL LENGTH: 320mm
 

ZERO BACKPLANE BOARD?VME-MONOLITHIC BUS?7-SLOT,BROOKS 921-057 REVAA,920-005 AA
 
KEMA KEUR POWER SUPPLY SPD14-2410P
 
OMRON GT1-OD16 GT1-BSCO2 DIGITAL UNIT, OMRON DRT1-COM COMMUNICATION UNIT
 

MKS INSTRUMENTS MFC?MASS FLOW CONTROLLER?649A12T51CAVR-S 500SCCM He
 
F65 WKS MB,E.F.634.5/2d 90.27 BOARD
 

YASKAWA AC SERVO MOTOR,SGM-01A312 WORKING
 
OMRON PLC HOST LINK?UNIT C200H-LK201-V1[2],C200H-LK202-V1[1] LOT OF 3
 

THK BEARING RB8016UUCC0 NEW
ACOPIAN A24H850M REGULATED POWER SUPPLY
 
PCL-722 144 DIO CARD?REV A2
 

BULGIN-SOURCE SAX51-01 POWER SUPPLY
 

FANUC INPUT UNIT A14B-0061-B103,A20B-0007-0340/06A
 

KLA TENCOR 655 652883 00 REV F2
 

GRANVILLE-PHILLIPS 275 MINI-CONVECTRON 275905-EU
 
MKS BARATRON PRESSURE TRANSDUCER 872B-25381
 

NEIMC LAMBDA ET-5B POWER SUPPLY
 
TYLAN CORP MFC MASS?FLOW CONTROLLER FC-260 200 SCCM CHF3
 

KITZ SCT DIAPHRAGM VALVE PCTFE-SEAT SCV?S20Y 316L 10K-1/4" LOT OF 2
 
KITZ SCT DIAPHRAGM VALVE PCTFE-SEAT SCV?S20Y 316L 10K-1/4" EP KD LOT OF 2
 

BENKAN SCV PCTFE-SEAT 316L 10K-1/4" EP KD LOT OF 2
 
MAXON MOTOR CONTROL?4-Q-EC AMPLIFIER
 
K2CPU3 SYNCOTEC BOARD
 

FUJI A50L-0001-0304#S 6MBP50RH060-01
 

FUJI A50L-0001-0327?6MBP50RTA060-01
 

POTTER & BRUMFIELD CNT-35-26 TEMPERATURE?CONTROLLER LOT OF 3
 
COPLEY DRIVER 412
 

THK BALLSCREW , TOTAL LENGTH 480MM TREVEL RANGE 340MM LEAD 5MM
 

HILSCHER GMBH DEVICENET PCI CARD CIF50-DNM, CIF50 BSL-DN V1.503
 
I.O DATA DEVICE GA-DVL2-3 BOARD
 

RELIANCE REMOTE I/O?COMMUNICATIONS MODULE 57C416,57416-S
 

ISERT STEPPING MOTOR?A2406-9212-A2,VEXTA?D6CL-6.3
 

NEC ISA-BDR BOARD,DTS-4073,TS-483-30201
 
PANASONIC AC SERVO MOTOR AMKA200G10KAC
 

OMRON PLC CPU UNIT C200HW-COM05-V1 C200HX-CPU34-E, FREE SHIPPING.
 

OMRON PLC OUTOUT UNIT C200H-OD219, LOT OF THREE.
 

KOLON INPUT MODULE 1C693MDL645R LOT OF 3, MANUFACTURED UNDER?LICENCE GE FANUC
 

KOLON INPUT MODULE 1C693MDL645R LOT OF 3, MANUFACTURED UNDER?LICENCE GE FANUC #1
 

FANUC POWER MATE D COMPONENT_ BOARD A20B-1004-0960
 

OMRON PLC MODULE C200H-DA001
 

KAIJO MOS ILL-001 383145C-1/2 ~ 2/2 BOARD
 

BECKHOFF MODULES BK5220 KL1154 4EA KL2184 3EA KL9010 1EA _#5
 

BECKHOFF MODULES BK5220 KL1154 4EA KL2184 3EA KL9010 1EA _ #8
 

BECKHOFF MODULES BK5220 KL1154 4EA KL2184 3EA KL9010 1EA - #4
 

VEXTA SPEPPING MOTOR?PMM33BH2 0.72' 0.75A WITH CRANK SHAFT
 

MITSUBISHI MR-C20A?200W SERVO DRIVER SINGLE PHASE
 

PANASONIC SERVO DRIVER MADDT1205 100W
 
SEALEVEL BOARD COMM+2/EX 3087 REV B
 

DC STABILIZATION POWER FA620#1
 
KEYENCE KV24R TESTED?WORKING
 

KEYENCE KZ-40T TESTED WORKING
 

HIGH SPEED SERIAL PORT CARD SIIG FCC ID:FK3SIIG4SKTF3
 

ROCKWELL SAMSUNG PLC?CPL9503 LOT OF THREE
 

VEXTA GEARED STEP MOTOR PMM33B-MG30 0.024 DEGREE PRE STEP
 

YASKAWA MINERTIA MOTOR UGRMEM-01SSW11
 
ELMO MOTION CONTROL?SSA 6/100 SERVO AMPLIFIER CARD PLUG-IN INCLUDING POWER MODUL
 

PRECISION RIGHT ANGLE REDUCER RATIO 20:1?KEG2-20R GOOD FOR 4TH AXIS
SMC VQ1200-5(4) VQ1100-5(6) VVQ1000-10A-1(2)
 

APPLIED MATERIALS AI?MUX/CURRENT SENSE ASSY. 0100-09011 REV:E BOARD
 

FUJI ELECTRIC AUTO?BREAKER EA103F 75A LOT OF 2
 

SMC VQ1200-5(2) VQ1100-5(1) VVQ1000-10A-1(9)
 

SMC VQ1200-5(4) VQ1100-5(5) VVQ1000-10A-1(3)
 
SMC VQ1200-5(4) VQ1100-5(6) VVQ1000-10A-1(2)
 
HANYOUNG DIGITAL CONTROLLER CX7/CF7 CX7-P6
 

TESCOM VALVE 12-1A211AAEM6EM64 NEW
 

Applied Materials AMAT 0100-09020 REV B?PCB ASSY, FUSE BOARD
 
MULTITEST BAUTEILSEITE BOARD 49..01.57.00
 

ORIENTAL MOTOR SUPER?VEXTA UDK5114N 5-PHASE DRIVER
 

NUDAQ DIN-50S REV A2?NNB
 

ANNAPOLIS MICRO SYSTEM FOXFIRE II 12399-0000 REV F BOARD
 

ALLEN-BRADLEY MODEL:?1771-OBD/C DC OUTPUT MODULE LOT OF 2
 
TYLAN CORP MFC MASS?FLOW CONTROLLER FC-260 10 SCCM N2
 

FUJIKIN DIAPHRAGM VALVE 316L-P LOT OF 3#2
 

TAMAGAWA SEIKI TBL-T?BRUSHLESS DC MOTOR?3275N125E21
 

99301-009-WCP BOARD
 

MYUNGJIN S.M. MDB-303EM(4), MITECHNO MDB-303E LOT OF 5
 

MITSUBISHI CC-LINK OUTPUT UNIT MODEL: AJ65SBTB1-32D LOT OF 2
 
SAMSUNG DC BRUSHLESS?MOTOR CSM-A3BB1ANT3?TESTED WORKING
 
YASKAWA SERVOPACK DRIVER SGDA-01ASP TESTED WORKING
 
YASKAWA SERVOPACK DRIVER SGDA-A5APY38
 

OMRON G3PX-260EUN POWER CONTROLLER
 

YASKAWA AC SERVO MOTOR SGMAH-01AAA21 TESTED WORKING
 

FANUC OUTPUT MODULE?OD64A
 
AVAYA TN2464BP BOARD?DS1 INTFC 24/32 HV2
 

FANUC BOARD A20B-0009-0021.02B
 

INTERFACE AZI-4905?BOARD P9607021
 

SIEMENS SIMATIC, 6ES5451-4UA12
 

MITSUBISHI MELSEC NETII A1SJ71AP21 PLC
 

EUROTHERM 7100A 25A/220V/SELF/XXXX/NONE/PA/XXXX/4MA20/ENG/YES/V2/XXXX/GRF/XXXX/X
 

SIEMENS 3RV1021-4AA10 AND SIEMENS 3RV1021-1HA10 NEW
 

ABB DSQC 249A 3HAA3563-AGA/1 BOARD
 

CONTEC COM-4[PCI]H?BOARD
 

CKD CORPORATION VALVE AMDSZ0-3US-1 NEW #1
 

MILLIPORE WG3NS2RR2,?WG3NS1RR2, MOTT CORPORATION POU-05-SV1?LOT OF 11
 

FUJIKIN DIAPHRAGM VALVE 316L 073258 #2
 

RKC INSTRUMENT INC.?TEMPERATURE CONTROLLER REX-F900 F900W801-VV CD-NN5-5N
 
RKC INSTRUMENT INC.?TEMPERATURE CONTROLLER REX-F900 F900FP04-V CD-NN5-5N
 

OPTICAL OBJECTIVE CHANGER BOARD 9978-104-01 REV F
 

TRENEW BACKPLANE BOARD VME-MONOLITHIC BUS 7-SLOT,V807J1J2EPDBS
 

Applied Materials AMAT 0100-09020 REV C?PCB ASSY, FUSE BOARD
 

RKC CB100 FD08-8*AB-5N/A/Y NEW
 

TOKYO BOARD PF-DB T-MESC/C BX81-070005-13,3M81-021319-11
 

MULTITEST BAUTEILSEITE BOARD 49.01.56.00
 

MULTITEST BAUTEILSEITE BOARD 49.11.18.00
 

OMRON REMOTE TERMINALS G72C-VID16 LINK TERMINALS B7AS-T6B6(2) BROKEN
COPAL PRESSURE SWITCH PG-35-103R-PVC 8Y2?NNB
 
COPAL PRESSURE SWITCH PG-35-103R-PVC 9G4?NNB
 

#0128 INFICON AG, FL-9496 BALZERS VACUUM?SWITCH VSA100A WITH?3m CABLE
 

OPTICAL FIBER FOR ILLUMINATORS 145cm CONNECTOR DIA. 13.0 &?30.0MM
 

OPTICAL FIBER FOR ILLUMINATORS 165cm HAMAMATSU 030702
 

OPTICAL FIBER FOR ILLUMINATORS 167cm CONNECTOR DIA 13.0mm 17.7mm
 

MINI LINEAR ACTUATOR?MOVING RANGE 30MM?NSK 08HX-0030 W0601MA-3PY-C3Z
 

MITSUBISHI MELSEC PLC AX42 INPUT MODULE
 

ENTEGRIS NT FLOW-THROUGH PRESSURE TRANSDUCER 4210-100G-F08-D00-A-P1-U1 NEW
 

SIEMENS SIMATIC, 6ES5420-4UA13 #1
 
CAPACITANCE DIAPHRAGM GAUGE MFG UNDER PATENT CMLHL-31-160S123
 

PURERON JAPAN MODEL:?PSD-04D SP11 LOT OF?2
 

SERIES LOVE CONTROLS?16L2034-992 9502 LOT OF 2
 

HANYOUNG DX4-KR LOT OF 2
 

CONTEC GP-IB[PC]L BOARD
 

MITSUBISHI CC-LINK D/A CONVERTER UNIT MODEL: AJ65SBT-62DA
 

ESC RMF B2 REV.1.0 BOARD
 

SIEMENS MICROMASTER?1790L220A
 

SIEMENS MICROMASTER?6SE6400-0EN00-0AA0
 

METRONIX S40-6-0400ZO ROTARY ENCODER NEW?LOT OF 2
 

METRONIX S40-8-1000VL ROTARY ENCODER NEW?IN BOX
 

HP 54650A HP-IB INTERFACE MODULE
 

SRC VME Systembus SVB-05VME Backplane
 

OMRON E5C3-WR20K TEMPERATURE CONTROLLER?LOT OF 2
 

FUJI ELECTRIC AUTO?BREAKER EA33 EA32 10A LOT OF 2
 

INFICON AG, FL-9496?BALZERS VACUUM SWITCH VSA100A
 

FANUC A20B-2002-0680/02A,A350-2002-T686/02 BOARD TESTED WORKING
 
HANYOUNG DIGITAL PANEL METER DP3-N DP3-NA20-7
 

AB, ALLEN-BRADLEY 24VDC SINK INPUT 1794-0B16 LOT OF 3
 
OMRON E2K-C25MY2 CAPACITIVE PROXIMITY SWITCH NEW
 

ADVANTECH PCI-1756 REV A1 01-2 BOARD
 
DAISAN KOGYO STEPPING MOTOR DRIVER ST16(FIVE-PHASE)
 

FLUOROWARE ES-1C-MD-XX CONTROL MODULE LOT OF 4
 

ASAHI KEIKI ASG-158-17-14 DIGITAL PANEL?METER
 
OMRON 3G8B2-AP000 BOARD 0228942-8E
 

TESCOM 100 PXIG MAX.?OUPLET CONN. SIZE:1/4 IN. GAS FLOW:100slpm MAX INLET 600PSI
 

PULSTEC BINARIZER BINA-SW PSB002DD-004-0, BINARIZER BINA- PANEL PSB002DD-003-0
 
MITSUBISHI PLC AJ65SBTC1-32DT1
 

NEC NL6448BC33-53
 

TAMAGAWA TS3653N3E9?STEP MOTOR
 

TAMAGAWA TS3653N2E6?STEP MOTOR
 

NATIONAL PCI-DIO-96?BOARD 182920J-01
 

FANUC BOARD A20B-0009-0031/01A
 

SIEMENS SIMATIC 6ES5470-4UC12
 
OMRON SYSMAC CS1W-DRM21-V1 COMMUNICATION LINK UNIT
 

OMRON SYSMAC REMOTE?TERMINAL DRT2 MD16TA?8-IN,8-OUT
 

SIEMENS SIMATIC,S7 1P 6ES7-131-4BD01-0AA0
 

MITSUBISHI HMI A951GOT-LBD GRAPHIC OPERATIONS TERMINAL,TOUCH?SCREEN