Phoenix Contact 1105523 A safe extension module is available with a specific configuration: it features 8 safe inputs and 2 safe outputs, along with 2 reset inputs, 2 signal outputs, and 4 clock outputs. The module also includes a TBUS interface and can operate up to SIL level 3 and Cat. 4/PL e safety standards, and comes equipped with a pluggable Push-in terminal block, complete with an included TBUS connector.