ET200S 1Count 24V/100kHz
The Siemens 6ES7138-4DA01-0AB0 is a single-channel counter module for the ET 200S distributed I/O system, rated for 24 V inputs at 100 kHz. This variant is the 1Count 24V/100kHz version — one counter channel, 24 V logic, 100 kHz maximum count frequency. That is the only functional specification the order code carries; no additional firmware options or temperature extensions are implied by the base part number.