1-16 L90 Line Current Differential System GE Multilin1.4 UR HARDWARE 1 GETTING STARTED1 1.4UR HARDWARE 1.4.1 MOUNTING AND WIRINGPlease refer to Chapter 3: Hardware for detailed mounting and wiring instructions. Review all WARNINGS and CAUTIONScarefully.1.4.2 COMMUNICATIONSThe EnerVista UR Setup software communicates to the relay via the faceplate RS232 port or the rear panel RS485 / Ether-net ports. To communicate via the faceplate RS232 port, a standard straight-through serial cable is used. The DB-9 maleend is connected to the relay and the DB-9 or DB-25 female end is connected to the PC COM1 or COM2 port as describedin the CPU communications ports section of chapter 3.Figure 1–7: RELAY COMMUNICATIONS OPTIONSTo communicate through the L90 rear RS485 port from a PC RS232 port, the GE Multilin RS232/RS485 converter box isrequired. This device (catalog number F485) connects to the computer using a “straight-through” serial cable. A shieldedtwisted-pair (20, 22, or 24 AWG) connects the F485 converter to the L90 rear communications port. The converter terminals(+, –, GND) are connected to the L90 communication module (+, –, COM) terminals. Refer to the CPU communicationsports section in chapter 3 for option details. The line should be terminated with an R-C network (that is, 120 :, 1 nF) asdescribed in the chapter 3.1.4.3 FACEPLATE DISPLAYAll messages are displayed on a 2 u 20 backlit liquid crystal display (LCD) to make them visible under poor lighting condi-tions. While the keypad and display are not actively being used, the display will default to user-defined messages. Any highpriority event driven message will automatically override the default message and appear on the display.
