Power-off operation (primary safety principle): It is strictly prohibited to plug or unplug modules while the system is powered on. Before connecting or disconnecting any signal lines, terminal blocks, or installing or replacing modules, all relevant power sources (including power supply and process voltage) must be cut off. Operating in hazardous environments while powered on may result in arcs, causing fires or explosions.

Preventing electrical damage: To avoid damage to the PLC module due to overvoltage or short circuits, it is necessary to ensure that all voltage sources are turned off before performing any operation. Do not connect any voltage or signal to the reserved terminals marked as "---" on the module, as these terminals may have internal voltage.

Be aware of signal interference: If connecting analog signals, use shielded cables and ground the cable shielding layer at both ends to reduce electromagnetic interference and prevent inaccurate measurements.

Confirm module compatibility: The TU515 is mainly used for connecting 24V DC digital modules and analog modules. Before purchasing or installing the accompanying I/O modules, please be sure to check ABB's official compatibility documentation to ensure that the module can be installed and used properly.

Distinguish special versions: The TU515 has a standard version and an XC (Extreme Conditions) version suitable for harsh environments. The XC version has a specific identification marked as "1SAP4..." in the part number and can be selected based on the actual environmental requirements.