1756-GTWYS/ABPLC模塊

RS-422的大傳輸距離為4000英尺（約1219米），大傳輸速率為10Mb/s。其平衡雙絞線的長度與傳輸速率成反比，在100kb/s速率以下，才可能達到大傳輸距離。只有在很短的距離下才能獲得高速率傳輸。一般100米長的雙絞線上所能獲得的大傳輸速率僅為1Mb/s。

　RS-422需要一終接電阻，要求其阻值約等于傳輸電纜的特性阻抗。在矩距離傳輸時可不需終接電阻，即一般在300米以下不需終接電阻。終接電阻接在傳輸電纜的遠端。

 1756-GTWYS/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