Siemens 6ES5700-1LA12 – Mounting Sub-Rack for SIMATIC S5 Modules

The Siemens 6ES5700-1LA12 provides a mechanical housing for up to 8 S5 I/O modules. This mounting sub-rack measures 482 mm in width and 290 mm in height. It has a depth of 200 mm, so it fits standard 19-inch cabinets. The unit weighs 4.8 kg, making floor or rack mounting secure.

Slot Configuration and Backplane Architecture

This sub-rack contains 8 slots arranged in a single horizontal row. The Siemens 6ES5700-1LA12 includes a passive backplane with no active components. Each slot accepts any standard S5 module up to double width size. The backplane distributes power and data signals to all inserted modules. A built-in DIN rail accepts power supply units and termination boards.

Connection to Central Controller and Power

You must connect this sub-rack to a central controller via an interface cable. The Siemens 6ES5700-1LA12 uses a 50-pin ribbon cable for remote I/O connection. This cable supports distances up to 100 meters between racks. The sub-rack requires an external 24V DC power supply for operation. A terminal block on the side accepts field power wiring easily.

Internal Components and Mechanical Design

The sub-rack contains one backplane PCB with etched signal traces. The Siemens 6ES5700-1LA12 includes a metal chassis for electromagnetic shielding. Four mounting brackets allow 19-inch rack or wall installation options. The unit stores 220 µF of capacitance across its voltage distribution traces. This storage filters noise from the incoming 24V DC supply effectively.

Environmental Specifications and Cooling

You can mount this sub-rack horizontally or vertically inside any cabinet. The device operates reliably from 0°C to 50°C ambient temperature. It tolerates humidity levels up to 90 percent without any condensation issues. The Siemens 6ES5700-1LA12 includes ventilation slots for passive convection cooling. An IP20 rating suits indoor panel installation in controlled environments.

Below is a complete summary of its technical specifications.

The Siemens 6ES5700-1LA12 expands I/O capacity without replacing the central controller. You do not need any special configuration software for this sub-rack. This unit also supports hot-swapping of most I/O modules during operation. Consequently, it provides flexible I/O expansion for large S5 automation systems.