Electrical Connection

The analog module is plugged on I/O Terminal Units TU515 or TU516 I/O Terminal Units TU515 and TU516 for I/O Expansion Modules. Properly seat the module and press until it locks in place. The Terminal Units are mounted on a DIN rail or with 2 screws plus the additional accessory for wall mounting (TA526 Wall Mounting Accessory TA526).

The electrical connection 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

Mounting, disassembling and electrical connection for the Terminal Units and the I/O modules are described in detail in the System Data S500 System Data, Overview .

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, independent of the inserted module:

Terminals 1.8, 2.8, 3.8 and 4.8: Process voltage UP = +24 V DC

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

The assignment of the other terminals:

Terminals Signal Meaning
2.0, 2.2, 2.4, 2.6 I0+ to I3+ Plus poles of the first 4 analog inputs
1.0, 1.2, 1.4, 1.6 I0- to I3- Minus 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+ Plus poles of the following 4 analog inputs
3.0, 3.2, 3.4, 3.6 I4- to I7- Minus 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 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 AGND/ZP minus inputs may accept a potential difference up to 20 V DC regarding 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 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 AI531.

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

Caution

Risk of damaging the PLC modules!

The PLC modules can be damaged by overvoltages and short circuits.

Make sure that all voltage sources (supply and process voltage) are switched off before you are beginning with operations at the system.

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 disturbances, no high requirement on precision), the shielding can also be omitted.

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Terminal assignment of the analog input module AI531

The module provides several diagnosis functions AI531 Analog Input Module.