Usable BaseUnits (BU)

BaseUnits with an appropriate number of terminals are available for single or multi-conductor connection.

All variants that correspond to the BU type of the I/O module used can be used as BaseUnits (see Selection and ordering data).

Load group formation

A light-colored BU separates the self-assembling, internal voltage buses (P1, P2, AUX) and thus opens a new load group. The power supply of a load group must be fed in at the light BU of this load group.

A dark BU forwards the power supply of the adjacent light BU on the left via the self-assembling voltage buses P1, P2 and AUX. A new infeed is therefore only required on the next light BU to the right. The setting of a further light BU is required whenever

• a new load group is to be formed (for example, for isolating the supply voltage from module groups) or
• the maximum current simultaneously required by the load group exceeds the permissible limit of 10 A.

Color identification of the terminals

The potentials at the terminals of the BaseUnit are defined by the inserted I/O module in each case. To prevent wiring faults, the potentials of the terminals can optionally be identified by means of module-specific color-coded labels. The color-coded label that matches the respective I/O module is defined by the color code CCxx of the I/O module. This color code is also printed on the front of the module.

In BaseUnits with the additional ten internally jumpered AUX terminals, these can also be identified with color-coded labels. For the ten AUX terminals, color-coded labels are available in red, blue, and yellow/green.

Labeling

Labeling strips

Labeling strips can be inserted on the front of the interface modules or I/O modules and individually labeled via STEP 7, macros, etc. No special additional holder is required. If required, they can be easily replaced with the component.

Equipment labeling plates

Equipment labeling plates enable the equipment to be easily identified (e.g. compliant with EN 81346). They are easily plugged onto the required component (interface modules, I/O modules and BaseUnits) and when required, they can be easily replaced with the component.

The following labeling components are available:

• Film labeling strips, light-gray, roll with 500 strips, perforated, for thermal transfer printers
• Film labeling strips, yellow, roll with 500 strips, perforated, for thermal transfer printers
• Card labeling strips (180 g/m²), light gray, DIN A4 sheets with 100 strips each, perforated, for laser printer
• Card labeling strips (180 g/m²), yellow, DIN A4 sheets with 100 strips each, for laser printer
• Equipment labeling plates, white, ten sheets each with 16 labels, for thermal transfer card printers or labels

System-integrated shield connection

For the space-saving and EMC-optimized connection of cable shields, a shield connection is available that is quick and easy to mount. This consists of one shield connection element that can be plugged onto the BaseUnit and one shield terminal for each module. The low-impedance connection to the functional ground (DIN rail) is achieved without any additional wiring by the user.