Siemens 6ES7540-1AD00-0AA0 SIMATIC S7-1500 CM PtP RS232 BA 19.2 kbit/s Communication Module

The Siemens 6ES7540-1AD00-0AA0 is a SIMATIC S7-1500 CM PtP RS232 BA point-to-point communication module for serial RS232 connections up to 19.2 kbit/s, supporting Freeport, 3964(R), and USS protocols through a 9-pin D-sub connector. It draws 50 mA from the backplane bus, consumes 0.75 W, and mounts directly on the S7-1500 rail alongside the CPU.

Technical Specifications

Selection Notes

The BA designation caps transmission at 19.2 kbit/s, a fraction of what faster modules in the same CM PtP family support: adequate for USS drive telegrams and slow Freeport links, but a bottleneck for high-throughput 3964(R) transfers. Choose this module when the connected RS232 device, such as a legacy sensor, printer, or USS-interface drive, does not exceed 19.2 kbit/s; links needing higher throughput or RS422/RS485 wiring call for a different module in the lineup. The 707 V DC-tested isolation between the backplane bus and interface protects the CPU side from field-side transients on the RS232 line.

Applications

Serial point-to-point links to legacy RS232 field devices on an S7-1500 station, including metering equipment, badge printers, and USS-protocol drives that communicate below 19.2 kbit/s. The 9-pin D-sub connector and RTS/CTS/DTR/DSR/RI/DCD auxiliary signal support match standard RS232 cabling without an adapter.