In addition to the ESX.3xl (l for large), an ESX.3xm (m for medium) is also available, which accords approximately with half an ESX.3xl with regard to the construction size and the number of inputs/outputs.
Both control units are suitable for safety-oriented applications up to Performance Level PL d or Safety Integrity Level SIL 2, and are based on a common architectural concept: The robust aluminum die cast housing with automotive plug-in connectors contains a fast 32-bit microcontroller with six MB Flash and four MB SRAM, four CAN interfaces, one serial interface, one buzzer and several LEDs.