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, 4.8, 1.9, 2.9, 3.9 and 4.9 are electrically interconnected within the I/O terminal units and always have the same assignment, independent 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
2.0, 2.2, 2.4, 2.6 I0+ to I3+ Positive poles of the first 4 analog inputs
1.0, 1.2, 1.4, 1.6 I0- to I3- Negative poles of the first 4 analog inputs
2.1, 2.3, 2.5, 2.7 I0A to I3A Connections A (supply) of the first 4 analog inputs
1.1, 1.3, 1.5, 1.7 I0B to I3B Connections B (analog ground) of the first 4 analog inputs
4.0, 4.2, 4.4, 4.6 I4+ to I7+ Positive poles of the following 4 analog inputs
3.0, 3.2, 3.4, 3.6 I4- to I7- Negative poles of the following 4 analog inputs
4.1, 4.3, 4.5, 4.7 I4A to I7A Connections A (supply) of the following 4 analog inputs
3.1, 3.3, 3.5, 3.7 I4B to I7B Connections B (analog ground) of the following 4 analog inputs

Caution

Analog sensors must be electrically isolated against the earth. In order to avoid inaccuracy with the measuring results, the analog sensors should also be isolated against the power supply.

Note

The “IxB” clamps (x=0..7) of the analog inputs are electrically connected to each other. They form an “Analog Ground Signal” (AGND) for the module.

Note

The negative AGND/ZP inputs may accept a potential difference up to 20 VDC with regard to the common reference potential. Observing this maximum voltage difference, analog current inputs of one module can be switched in series to each other and also with current inputs 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 VDC power supply at the terminals L+/UP and M/ZP of the CPU/bus module increases by 2 mA per AI531.

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

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Terminal assignment of the module

The module provides several diagnosis functions AI531 - Analog Input Module.