Electrical \ Connection

The modules are plugged on I/O terminal units TU515 or TU516 TU515, TU516, TU516-H and TU542 for I/O Modules. Properly position the modules and press until they lock in place. The terminal units are mounted on a DIN rail or with 2 screws plus the additional accessory for wall mounting (TA526 TA526 - Wall Mounting Accessory).

The electrical connection of the I/O channels is carried out using the 40 terminals of the I/O terminal unit. I/O modules can be replaced without re-wiring the terminal units.

Note

For a detailed description of the mounting, disassembly and electrical connection of the module, please refer to the System Assembly chapter AC500-eCo.

The terminals 1.8, 2.8, 3.8 and 4.8 as well as 1.9, 2.9, 3.9 and 4.9 are electrically interconnected within the I/O terminal units and have always the same assignment, irrespective of the inserted module:

Terminals 1.8, 2.8, 3.8 and 4.8: process voltage UP = +24 VDC

Terminals 1.9, 2.9, 3.9 and 4.9: process voltage ZP = 0 V

The assignment of the other terminals:

Terminals Signal Description
1.0 to 1.3 I0- to I3- Negative poles of the 4 analog inputs
2.0 to 2.3 I0+ to I3+ Positive poles of the 4 analog inputs
3.0 to 3.3 O0- to O3- Negative poles of the 4 analog outputs
4.0 to 4.3 O0+ to O3+ Positive poles of the 4 analog outputs

Note

The negative poles of the analog inputs are electrically connected to each other. They form an “Analog Ground” signal for the module. The negative poles of the analog outputs are also electrically connected to each other to form an “Analog Ground” signal.

Note

There is no galvanic isolation between the analog circuitry and ZP/UP. Therefore, the analog sensors must be galvanically isolated in order to avoid loops via the earth potential or the supply voltage.

Note

Because of their common reference potential, analog current inputs cannot be circuited in series, neither within the module nor with channels of other modules.

Note

For the open-circuit detection (cut wire), each analog input channel is pulled up to “plus” by a high-resistance resistor. If nothing is connected, the maximum voltage will be read in then.

The internal power supply voltage for the module’s circuitry is carried out via the I/O bus (provided by a bus module or a CPU). Thus, the current consumption from 24 V DC power supply at the terminals L+/UP and M/ZP of the CPU/bus module increases by 2 mA per I/O module.

The external power supply connection is carried out via the UP (+24 V DC) and the ZP (0 V DC) terminals.

Attention

:strong:Risk of damaging the PLC modules!

Overvoltages and short circuits might damage the PLC modules.

  • Make sure that all voltage sources (supply and process voltage) are switched off before you begin with operations at the system.
  • Never connect any voltages or signals to reserved terminals (marked with —). Reserved terminals may carry internal voltages.

Note

Generally, analog signals must be laid in shielded cables. The cable shields must be earthed at both sides of the cables. In order to avoid unacceptable potential differences between different parts of the installation, low resistance equipotential bonding conductors must be laid.

Only for simple applications (low electromagnetic disturbances, no high requirement on precision), the shielding can also be omitted.

The following figure shows the electrical connection of the I/O module.

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Terminal assignment