1756-IA16/ABPLC模塊
常情況下,發(fā)送驅動器A、B之間的正電平在+2~+6V,是一個邏輯狀態(tài),負電平在-2~6V,是另一個邏輯狀態(tài)。另有一個信號地C,在RS-485中還有一“使能”端,而在RS-422中這是可用可不用的。“使能”端是用于控制發(fā)送驅動器與傳輸線的切斷與連接。當“使能”端起作用時,發(fā)送驅動器處于高阻狀態(tài),稱作“第三態(tài)”,即它是有別于邏輯“1”與“0”的第三態(tài)。
接收器也作與發(fā)送端相對的規(guī)定,收、發(fā)端通過平衡雙絞線將AA與BB對應相連,當在收端AB之間有大于+200mV的電平時,輸出正邏輯電平,小于-200mV時,輸出負邏輯電平。接收器接收平衡線上的電平范圍通常在200mV至6V之間。
1756-IA16/ABPLC模塊
1756
MFR. PART NUMBER DESCRIPTION
1756-A10 10 SLOT CONTROLLOGIX CHASSIS
1756-A13 13 SLOT CONTROLLOGIC CHASSIS
1756-A17 CHASSIS 17 SLOT CONTROLLOGIX
1756-A4 4 SLOT CONTROLLOGIX CHASIS
1756-A7 7 SLOT CONTROLLOGIX CHASSIS
1756-BA1 LOGIX5000 BATTERY ASSEMBLY
1756-CFM 2 CHANNEL /2 OUT CONFIGURABLE FLOWMETER
1756-CNB CONTROLNET BRIDGE MODULE
1756-CNBR CONTROLNET REDUNDANT BRIDGE MODULE
1756-CP3 LOGIX5000 RS232 PROGRAMMER CABLE
1756-DHRIO 2 CHANNEL DH+ AND/OR RIO SCANNER
1756-DNB DEVICE NET BRIDGE/SCANNER MODULE
1756-DPALEN CONTROLLOGIC SYSTEM DOCUMENTATION SET PRINTED
1756-ENET ETHERNET/IP BRIDGE MODULE
1756-GTWY CONTROLLOGIC GATEWAY CONFIGURATION SOFTWARE
1756-GTWYR SUPT REINSTATEMENT CONTRACT FOR 1756GTWY
1756-GTWYS SUPT RENEWAL CONTRACT FOR 1756GTWY
1756-HSC 2 CHANNEL /4 OUTPUT HIGH SPEED COUNTER
1756-IA16 79-132 VAC INPUT 16PTS
1756-IA16I 79-132 VAC ISOLATED INPUT 16PTS
1756-IA8D VAC DIAGNOSTIC INPUT 8PTS
1756-IB16 VDC INPUT 16PTS
1756-IB16D VDC DIAGNOSTIC INPUT
1756-IB16I VDC ISLOTED INPUT 16PTS