Siemens 6ES7541-1AD01-0AB0 Industrial Automation Module. Siemens 6ES7541-1AD01-0AB0 is the exact manufacturer order number for a industrial automation module in the SIMATIC S7-1500 portfolio. Siemens describes this exact reference as: SIMATIC S7-1500, CM PTP RS232 HF communications module for serial connection RS-232, freeport, 3964(R), USS, Modbus RTU master, device, 115200 bit/s, 9-pin D-sub plug. The verified manufacturer lifecycle record is PM300: Active Product.