Mounting and wiring
4.4 Power supply
This power supply unit is equipped with an I/O interface, which permits connection of the Beckhoff Bus
Terminals. The power is supplied via the upper spring-loaded terminals labelled “24V” and “0”V.
The CX system is supplied with 24 V DC (-15 %/+20%) via the internal bus and the Bus Terminals. The
dielectric strength of the power supply unit is 500 V
rms
. Since the internal bus in the terminals (K- and E-bus)
only transfers data, a separate power supply is required for the Bus Terminals. This is provided by means of
the power contacts, which are not connected to the power supply.
Requirements for the 24 V power supply
In order to guarantee the operation of the CPU (CX51x0 module) and the terminal strand in all cases, the
power supply must supply 4 A at 24 V.
The terminals are implemented in spring force technology. Connect the cables as follows:
1. Open a spring-loaded terminal by slightly pushing with a screwdriver or a rod into the square opening
above the terminal.
2. The wire can now be inserted into the round terminal opening without any force.
3. The terminal closes automatically when the pressure is released, holding the wire safely and
permanently.
CX51x0 35Version: 1.6