EMC requirements

AN4625

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DocID027187 Rev 1

4.5

Conducted disturbance tests (IEC 61000-4-6)

The conducted radio frequency interference test must be applied to all input pins of the

system. The frequency range is from 150 kHz to 80 MHz, with 80% amplitude modulation 1

kHz sinusoidal wave. A CDN (coupling/decoupling network) or a current coupling clamp (as

described in the IEC 61000-4-6 standard) must be used to apply stress to the system. The

required level is: 3 VRMS, whatever the tested system input is. The PLC system continues

operating. No loss of function or performance is acceptable (criteria “A” according to the IEC

61131-2 standard).

4.6

Reverse analog input polarity tests

The test procedure is described in the IEC 61131-2 standard (section 5.4.4.5 of Ed2 of the

standard). A signal of reverse polarity (negative voltage) for unipolar analog inputs is applied

for 10 seconds. The result of this test is stated by the manufacturer. Each input of the

CLT01-38S4 device may be biased to a reverse polarity. This case corresponds either to a

connection mistake, or a reverse biasing that is generated by the demagnetization of a

monitored inductive solenoid. The involved input withstands the high reverse current up to

20 mA; its corresponding bit in the data frame remains in a logic low-state. The other inputs

remain operative. By considering the supply operation, a reverse blocking diode can be

connected between the module ground and the common COM pin to protect the application

(especially the serial resistors) from a spurious reverse supply connection.

4.7

EMC testing

The EMC requirements according to the IEC 61131-2 standard have been verified.

Application tests show much better results than those given by the industrial standard. Test

requirements and results are listed in the table below. No additional protection device has

been used in the application.

Table 3. EMC immunity test requirements and results

Minimum requirements of international

standards *

CLT01-38S4 robustness

Tests conditions

Level/criteria

Test conditions

Level/

criteria

ESD test

IEC61000-4-2

Air discharge

±8 kV B

On product +

±15 kV B

Contact discharge

±4 kV B

On product +

±8 kV B

Burst test

IEC61000-4-4

Analog input

±1 kV B

STEVAL-IFP023V1,

2MHz

±3 kV A

DC power line

±2 kV B