FFDesignchnColby汇编.ppt

* * * * * * Topology – FISCO Fieldbus Intrinsically Safe Concept Host Computer H1 Interface 24VDC Wiring components Device 1 Device 3 Device 2 T IS Wiring Block Terminator IntrinsicallySafe Spurs This concept is applied to: Ex i/FISCO instruments in Zone 1 or 0 Intrinsic safeFF Power Supply ConditionerTerminator FISCO Power supply Intrinsically Safe Trunk T FFPS T * Topology – FISCO Advantages of FISCO優點: Trunk and Spurs are intrinsically safe 皆本質安全防爆 High reliability (design same as conventional isolator) 可靠度高 (和傳統的本安隔離器相同設計) Up to 16 instruments (limited by host) 可連接 16 個儀錶 (由監控電腦決定) Economically efficient經濟效益高 Standardized Ex parameters – no verification of intrinsic safety required 防爆各項參數計算標準化–本安儀錶安全參數計算時不需不需逐一比較 Verification of intrinsic safety documented by FISCO/FNICO (IEC 60079-27)獲本安認證 (IEC 60079-27) Highest safety (all Ex i) - no mix of protection methods 安全性最高 (全為本安設備) -不需使用不同保護原理的防爆設備 * Typical Segment Calculation: 8 fieldbus devices in IIB 12.9V 1 2 3 4 5 6 8 Redundant FISCO 9.5V min 9.63V For 8 fieldbus devices @ 17mA/device Consider one device in short-circuit ∑i = (7 x 17) + 42 + 3 = 164mA Assume 9.5V @ field devices 0.5V margin over FF limit Assume 1.5mm2 cable 24.0 ohms/km loop Assume 60m spur length: Voltage drop in spur = 0.017 * 24 *(60/1000)= 0.03V Voltage @ Megablock trunk= 9.5 + 0.03 + 0.1 = 9.63V Max. voltage drop in cable= 12.9 – 9.63 = 3.27V Rcable max = 3.27/0.164 = 19.94 ohms Max cable length= (19.94 * 1000)/24 = 831m IS Megablock Rcable max Note: Average current consumption is 15.29mA, see here: /showthread.php?p=5181#post5181 Physical LayerFISCO Host Computer H1 Interface 24VDC Device 1 Device 3 Device 2 T Ex nL Wiring Block Terminator Safe (Ex nL)Spurs Safe energy limitedFF Power Supply ConditionerTerminator Safe (Ex nL) Trunk T FFPS T FF vs 传统方案设计 FF总线物理層限制因素 FF通讯处理因素 应用区域及相应方案 接地及诊断设计 FF部件及现场实例 目录 * 接地方式 Device 1 Device 3 Device 2 T Wiring Block Terminator FFPS T FF Power Supply