DL405 Remote I/O System Manual

This document describes the DL405 series remote I/O system, which uses a Remote Master module (D4-RM) in the CPU base to control up to seven Remote Slave modules (D4-RS or D4-RSDC) over a twisted pair cable up to 3,300 feet. It details specifications, maximum I/O points per CPU model (D4-430, D4-440, D4-450), and the asynchronous communication between the Remote Master and CPU.