XBT-R400 Schneider ADS1110是精密的連續(xù)自校準(zhǔn)A/D轉(zhuǎn)換器,帶有差分輸入和高達(dá)16位的分辨率。片內(nèi)可編程的增益放大器PGA提供高達(dá)8倍的增益,并且允許以高分辨率對(duì)較小的信號(hào)進(jìn)行測(cè)量。
1ADS1110芯片結(jié)構(gòu)及工作原理
1.1ADS1110芯片結(jié)構(gòu)
ADS1110由△-∑A/D轉(zhuǎn)換器、可程控增益放大、2.048 V的電壓基準(zhǔn)、時(shí)鐘振蕩器和I2C總線接口組成,其結(jié)構(gòu)如圖1所示。
1.2ADS1110工作原理
ADS1110模數(shù)轉(zhuǎn)換器是由1個(gè)差分開關(guān)電容△-∑調(diào)節(jié)器和1個(gè)數(shù)字濾波器組成。調(diào)節(jié)器測(cè)量正模擬輸入和負(fù)模擬輸入的壓差,并將其與基準(zhǔn)電壓相比較,數(shù)字濾波器從調(diào)節(jié)器接收高速位流,并輸出一個(gè)代碼。該代碼是一個(gè)與輸入電壓成比例的數(shù)字,這個(gè)數(shù)字被限定在一定范圍內(nèi),范圍取決于代表輸出碼所需要的位數(shù)。在ADS1110中,基準(zhǔn)電壓為2.048 V,該基準(zhǔn)通常用作A/D轉(zhuǎn)換器的電壓基準(zhǔn),不允許接外部基準(zhǔn)。ADS1110只能采用內(nèi)部電壓基準(zhǔn),而且該基準(zhǔn)不能直接測(cè)得,也不能被外部電路使用。
2 ADS1110在稱重測(cè)量中的應(yīng)用
數(shù)字電子稱是日常生活中廣泛使用的一種稱量工具,市場(chǎng)上使用的各式小量程電子稱存在一定的局限性,這些電子稱體積大、成本高、計(jì)量誤差大。本文提出的電子稱選用低功耗、超低價(jià)控制芯片STC89C51RC和16位△-∑A/D轉(zhuǎn)換器ADS1110,設(shè)計(jì)一種體積小、低成本、計(jì)量精度高、工作可靠的小量程電子稱。
ADS1110與STC89C51RC單片機(jī)組成的稱重系統(tǒng)的硬件原理如圖2所示。
設(shè)計(jì)中選用單點(diǎn)式荷重傳感器LC8020,其精度為0.03%,靈敏度(2.0±0.2)mV/V,額定量程5 kg,供橋電壓5 V。當(dāng)稱重傳感器滿負(fù)載5 kg時(shí),傳感器輸出電壓變化(10±1)mV,此時(shí)要求加入ADS1110的電壓為1 024mV。設(shè)計(jì)配置8位ADS1110寄存器如表1所列。
ST/DRTY位的含意取決于它是被寫入還是被讀出。在單周期轉(zhuǎn)換方式中,寫1到ST/DRTY位則轉(zhuǎn)換開始,寫入0無影響;在連續(xù)方式中,ADS1110忽略寫入ST/DRTY的值。在進(jìn)行讀操作時(shí),ST/DRTY雨表明輸出寄存器中的數(shù)據(jù)是否為新數(shù)據(jù)。如果ST/DRTY為0,則剛從輸出寄存器中讀出的數(shù)據(jù)是新數(shù)據(jù);如果ST/DRTY為1,則剛從輸出寄存器讀出的數(shù)據(jù)以前已經(jīng)被讀取過。
保留位位6和位5置為0。SC位控制ADS1110是以連續(xù)轉(zhuǎn)換方式工作還是以單周期轉(zhuǎn)換方式工作,置SC為1時(shí),ADS1110以單周期轉(zhuǎn)換方式工作。DR的位3和位2控制ADS1110的數(shù)據(jù)速率,置DR的位3和位2為1表示ADS1110的數(shù)據(jù)采樣率為15 sps。PGA的位1和0控制ADS1110的增益,置PGA位1和0為1、0表示ADS1110的PGA增益為4。
3軟件設(shè)計(jì)
按照硬件電路,采用匯編語言編程,在KeilA51 V8.50環(huán)境下調(diào)試通過,并成功應(yīng)用在單片機(jī)稱重系統(tǒng)中。軟件按功能模塊,主要由LCD顯示控制、ADS1110模數(shù)轉(zhuǎn)化、超負(fù)荷報(bào)警檢測(cè)、采集數(shù)據(jù)處理、鍵盤中斷等子程序構(gòu)成。此處側(cè)重介紹ADS1110模數(shù)轉(zhuǎn)換程序。
XBT-R400 Schneider XYCOM 97957-101 MONITOR
XYCOM 99566-001 9403 MONITOR
XYCOM 99566-021 9403 MONITOR
XYCOM CPU-XVME-675 CPU CONTROL BD
XYCOM CS8500 TERMINAL
XYCOM IC1500T-ABNOS06 OPERATOR INTF
XYCOM PCS82034B CONTROL BOARD
XYCOM PCS83594A MEMORY BOARD
XYCOM PM101229 PMXVME-230 BD
XYCOM PM4153/B PC/AT TERMINAL
XYCOM PM9403R COLOR MONITOR
XYCOM PM9450 IND WORKSTATION
XYCOM PM9485 IND WORKSTATION
XYCOM PM9487T IND WORKSTATION
XYCOM SXT1811T OPERATOR INTF
XYCOM SXT1811T-A OPERATOR INTF
XYCOM XVME-100 MEMORY MODULE
XYCOM XVME-113 VME BUS BOARD
XYCOM XVME-230 VME BUS BOARD
XYCOM XVME-290 VME BUS BOARD
XYCOM XVME-293 VMEBUS BOARD
XYCOM XVME-404 MULTI DRIVER BD
XYCOM XVME-500/4 XVME BOARD
XYCOM XVME-530 ANALOG I/O BD
XYCOM XVME-540 AIO MODULE
XYCOM XVME-566 ANALOG I/O BD
XYCOM XVME-600 PCB
XYCOM XVME-601 PCB
XYCOM XVME-630 XVME 630 BOARD
XYCOM XVME-653 CONTROL BOARD
XBT-R400 Schneider
GE FANUC IC600BF831K IC600BF831
GE FANUC IC600CB502D IC600CB502
GE FANUC SERIES SIX IC600BF940L IC600BF940
GE FANUC SERIES SIX IC600CB503A IC600CB503
GE FANUC SERIES SIX IC600YB929A IC600YB929
GE FANUC SERIES SIX IC600BF914K IC600BF914
GE FANUC SERIES SIX IC600YB941B IC600YB941
GE FANUC SERIES SIX IC600YR511A IC600YR511 NEW
GE FANUC JUNIOR IC609SJR120C IC609SJR120 NEW
GE Fanuc A06B-0163-B175 AC SERVO M9/3000
GE Fanuc BOARD A16B-2200-0121/06C A16B-2200-0121 BASE0
GE Fanuc BOARD A16B-2200-0854/05B A16B-2200-0854 NEW
GE Fanuc BOARD A16B-2200-0842/08F A16B-2200-0842 NEW
GE Fanuc JA13 8008-T561 PULSE GENERATOR CABLE L7R003
GE Fanuc IC800SSI104RS1-DE IC800SSI104RS1 IC800SSI104
CTC PARKER AUTOMATION P15-044DR-3 P15-044DR P15 044DR
GE Fanuc BOARD A20B-1003-0230/11C A20B-1003-0230
GE Fanuc BOARD A16B-2200-0171/07A A16B-2200-0171
GE Fanuc BOARD A16B-2200-0471/08B A16B-2200-0471
GE Fanuc BOARD DA16B-1212-0030 A16B-1212-0030
GE Fanuc A02B-0094-C103 CASSETTE
GE Fanuc A05B-2300-C003 BACK PLANE 5 SLOT
GE Fanuc A02B-0236-C205 SDU1 INT MODULE
GE Fanuc A02B-0236-C203 SDU1 DET MODULE
GE Fanuc A290-0561-V532 A860-0320-T112 ABS2500P PULSE
GE Fanuc A16B-2201-0791/02B A16B-2201-0791 VISION
GE Fanuc A860-0320-T011 ABS PULSE CODER
GE Fanuc A16B-2201-0800/02A A16B-2201-0800 /03B
GE Fanuc A16B-2200-0853/03B A16B-2200-0853 BOARD
GE FANUC A03B-0808-C200 BMD88P1 MODULE
GE Fanuc A05B-2300-C002 BACKPLANE 4 SLOT
GE Fanuc A16B-2200-0852/03B A16B-2200-0852
GE FANUC A03B-0808-C010 BMD88A1 MODULE
GE Fanuc A16B-2200-0841/07E A16B-2200-0841 BOARD
GE FANUC A860-0360-T061 ALPHA A64 PULSE CODER
GE Fanuc A05B-2047-C181 PURGE UNIT
GE FANUC A860-0360-V501 ALPHA A64 PULSE CODER
GE FANUC A860-0346-T061 SERIAL PULSE CODER
GE Fanuc IDEC IZBARL IBRC410 IBRC 410 RELAY BARRIER
GE FANUC A02B-0163-C382 A16B-2300-0085 LCD/MDI
GE Fanuc INTRINSPAK 8901/31-280/085/00 8901 31 STAHL
TELEMECANIQUE ATV58EU18N4FZU ATV58EU18 NEW
TELEMECANIQUE ATV58EU72N4FZU ATV58EU72 NEW
GA FANUC HORNER HE670ADC810D HE670ADC810 ANALOG NEW
YASKAWA DRIVE CIMR-V7AM23P7 CIMR-V7AM23P71 NEW
GA FANUC IC693MDL740C IC693MDL740D IC693MDL740 E NEW
GA FANUC IC693MDL740C IC693MDL740 OUTPUT 12/24VDC
GA FANUC A16B-2100-0423/03C A16B-2100-0423 BOARD
GA FANUC A06B-0373-B569 #7076 SVMTR 1-OSP/300
GA FANUC EE-4696-211-009 EE-4696-210-000 P500 ENCODER N
ALLEN BRADLEY POWERFLEX 700 20B D 2PI A3 AYNANC0
GE Fanuc BOARD A16B-2200-0854/03B A16B-2200-0854
OMRON AC SERVO DRIVER R88D-WN20H-ML2 R88D WN20H ML2 NEW
OMRON AC SERVO MOTOR R88M-W2K030T-S2 R88M W2K030T NEW
OMRON AC SERVO MOTOR R88M-W1K030H-BS2 R88M-W1K030H NEW
GE FANUC PROGRAMMER A02B-0118-C042
GE Fanuc A05B-2401-C311 I/O PSU UNIT
GE Fanuc CNC REGULATOR 2C 44A394633-G01 44A394633G01
GE Fanuc A06B-0314-B574 #7000 MODEL 5S NEW MOTOR
NIB GE Fanuc P BASE A16B-2200-0020/02B A16B22000020