6ES7403-1TA01-0AA0

Siemens 6ES7403-1TA01-0AA0 is an ER1 extension rack for SIMATIC S7-400. The rack provides eighteen positions for signal modules and can accommodate two power-supply modules in a redundant supply arrangement. It forms part of an S7-400 installation rather than operating as an independent controller; the installed CPU, interface modules, power supplies and signal modules determine the finished system.

The ER1 backplane provides a P bus and does not provide the communication bus. This distinction matters when selecting extension-rack locations and deciding which modules can be installed. The manufacturer data gives an ambient operating range of 0 to 60 °C for the rack. Examine the fitted modules and the expansion-cable topology before assuming that another rack type or position is interchangeable.

For a rack replacement, record the existing slot assignment, power-supply arrangement and expansion connections. Verify the mechanical mounting, backplane contacts and module latches, then reinstall modules in their approved positions. After energization, check supply indication, rack communication through the intended interface and diagnostics for every affected signal module under the project acceptance procedure.