User Manual
 7000 Bus Converter User’s Manual (Version 1.8  Jan/2006, 7PH-006-18)  --------------- 12 
2.2 I-7520R: 
2.2.1 Pin Assignment and Specifications: 
7520R: RS-232 to RS-485 Converter 
•  Protocol: two-wire RS-485, (D+, D-), protocol 
•  Connector: plug-in screw terminal block 
•  Speed: “Self Tuner” inside, auto switching baud 
rate, from 300 to 115200 BPS 
• 256 modules max in one RS-485 network 
without repeater 
•  2048 modules max in one RS-485 network with 
repeater 
• Isolation voltage: 3000V 
• Isolation site: RS-485 
• Repeater request: 4,000 feet or over 256 
modules 
•  Power requirements: +10V dc ~ +30V dc 
•  Power consumption: 0.05A@24V; Max 
2.2.2 Block Diagram: 










