3UF5900-1GA00 Constructive flaw in Siemens Constructive flaw in Siemens Simocode. This type of connector is specially designed for connecting a PROFIBUS cable to Simocode devices (3UF 5001-3BN00-1, 3UF 5010-3BN00-1, 3UF 5021-3BN00-1, 3UF 5031-3BN00-1, 3UF 5041-3BN00-1) At first glance, these connectors are very convenient, and they cost one and a half times cheaper than front connectors for a DB9 socket. However, the operation of these connectors has revealed a number of serious shortcomings.