| 价格 | 面议 |
|---|---|
| 品牌 | 进口 |
| 区域 | 全国 |
| 来源 | 厦门兴润星贸易有限公司 |
详情描述：
RADISYS EPC-22 西门子的计数器C1、C2等大能接受什么频率的脉冲呢？什么时候必须采用高速计数呢？这个是看PLC的什么指标算出来的？ 答：PLC的计数器在计数脉冲的上升沿时计数。计数器实际上是一种“软件”计数器，与PLC的扫描工作方式有关。PLC在每个扫描周期开始的时候读取数字量输入的值。如果前一扫描周期读取的是0、本次扫描周期读取的是1，操作系统就知道出现了计数脉冲的上升沿，将计数器的当前值加1或减1。下图假设PLC的扫描周期和计数脉冲的周期都是恒定的。如果计数脉冲的周期小于2倍扫描周期，就会丢失计数脉冲的上升沿。实际上PLC的扫描周期不是恒定的，由于程序的跳转或中断等原因，都会使扫描周期增大，导致丢失计数脉冲的上升沿。计数脉冲的高电平和低电平脉冲的宽度小于扫描周期，也会丢失脉冲的上升沿。实际工作中可以用STEP7读取扫描周期大致的平均值，计数器的大计数脉冲的频率应比它的两倍的倒数小一些。小得越多越保险。如果不能满足要求，只有改用高速计数器。 Pepperl Fuchs Inductive proximity switch NJ4-12GK-N P F NOKIA CC500 VPN Firewall CryptoCluster 500 spare DYNAX YUDO-STAR YUCON-400 TT53-0C-102-GYS Control Panel DYNAX Atoms DMC-2X DNX1312 Drive NEW SPARE POLE STAR DSAS-L Ship Security Alert SKYWAVE DMR-200 HAAS 93-5220C KRISTEL LP 28HM-NM4 CRT Nortel I2004 IP Phone NTDU82ba EtherGray Honeywell LSQA6B134 Heavy Duty Micro Limit Switch LUCENT PCBR850-Predist?ortionCDMA Baseband RADIO 44WR87 Thrane & Thrane DC AC Battery Alarm module 51564 24 97 DLPCinema 1.45-2.05:1 High Brightness Len 108-335102-01 DLPCinema 1.25-1.45:1 High Brightness Len 108-274101-01 LINCOLN 84015 series D Lube Timer STULZ Cosmotec Industrial Cooling EHE2800220Z000K 220V SIEMENS 5WG1 263-1EB11 BINARY INPUT DEVICE USED Messer Sesomat ALFA Controller 768.01030 Lot of 27 VITESSE VSC7153SS-02 chips 0736 Nippon MS Compact Motorized Ball Valve AM2MS205UUP ERICSSON ROF1377846/1 R1D ETB/ETP Board NORTEL NTHW18BF 6mPKTservSP function processor NORTEL NTHW18BB 6mPKTservSP function processor Boeing 65B03189-37 607XZO SEAL Fabric Covered Rubber New OMRON S82J-05024D POWER SUPPLY Mitsubishi CM600HA-24A 1200V 600A IGBT used Infineon powerblock TD285N16KOF used HP Agilent 05518-60003 Laser Control Reference Board Lot 10 Bimetal thermostat PST3-RJ001 Pacific Controls AIS-CTRX classe B transponder True Heading 20060701-1 Agilent G1978-60027 Charging Electrode Mount Assy NetApp CF boot card PLRXPL-VI-S24-2?2 FTRJ8519P1BNL Phoenix Contact IBS CT 24 IO GT-T IBSCT24IOGT-T InterBu Lot 8 OMRON Relays MY4N 200/220vAC MY4N-D2 24VDC OMRON H3CR-H8L 0.6M-12M Delay TIMER 24VDC/AC OMRON H3CR-H8L 0.6M-12M Delay TIMER DC100-125V OMRON H3CR-H8L 0.6s-12s Power Off Delay TIMER AC120V PACKETEER PacketSeeker 8500 PS8500-L000M PACKETEER PacketSeeker 8500 PS8500-L000M-5000 ISP Lot 500 Tantalum Capacitor T496C106M016AS 10UF 16V 20% Honeywell DATAMATE 9303004 DM100PS1WG PressureTransmitt Honeywell Model EA PressureTransducer 9308308 0-300psig Lot 3 Honeywell MLH700SCD1206 MLH Pressure Sensors USED Lot 3 Honeywell MLH010BGD14E MLH Pressure Sensors USED NeoScale CryptoStor Tape 700 SC702R Gigahertz Solutions High Frequency Analyser HF 59B AsIs BW 118219 M5-PR-1 Motorized Pump Yellow GasAlertMicro 5 Smema Interface Module 60.009.037 Lam RESEARCH Node Board 810-800256-005 Rev A PACKETEER PacketSeeker 9500 PS9500-L000M-2000 PACKETEER PacketSeeker 9500 PS9500-L000M-2000-SX Lot 3 Honeywell 04359FFFF-60 MLH Pressure Sensors USED MITSUBISHI MELSEC A/D CONVERTER UNIT A1S64AD NEWsurplus Lot 3 Honeywell DG 9251325 9251316 9250908 PressureTran MITSUBISHI MELSEC POWER SUPPLY A1S63P Like Lot 3 Honeywell MLH550BST12A MLH550BST10E MLH08KPST12A HP 409303-001 FAN HEATSINK for DC5750 etc BLUECOAT SG8000-1 PROXY SERVER WEB ACCELERATOR BLUECOAT 8000-1 PROXY SERVER WEB ACCELERATOR 080-03103 BLUECOAT SG8000-3 PROXY SERVER WEB ACCELERATOR BLUECOAT SG8000-2 PROXY SERVER WEB ACCELERATOR Honeywell ECLIPSE Pressure Transducer 9253540 used Honeywell ABHP Pressure Transducer 9220106 0-6PSIG USED Honeywell ABHP Pressure Transducer 9220706 0-25PSI USED Honeywell ABHP Pressure Transducer 9222502 200PSIG USED Lot 3 Honeywell ML025BS2PG ML025PG1PG ML250BS2PR10 USED Lot 3 Honeywell 19C050PA1K/SZ75?94 Pressure Sensors USED Lot 3 Honeywell 19C010PG5K Pressure Sensors USED Lot 3 Honeywell 19C050PG3K Pressure Sensors USED
| 联系人 | 何雄欣 |
|---|
