Echelon FT 3150 Smart Transceiver - Manual (Page 111)

FT 3120 / FT 3150 Smart Transceiver Data Book 105
EN 61000-4 Electromagnetic Compatibility (EMC) Testing
For more information on levels and installation classes, see EN 61000-4-5. The applicable surge test levels and
coupling mode specified by EN 61000-4-5 can be found in Table A.1 of that document as follows:
• Balanced circuits/lines;
• Coupling mode is line-to-ground, either polarity;
• Surge waveform is 1.2/50µs (8/20µs) combination wave for classes 1-4.
EN 61000-4-6 Conducted RF Immunity testing is performed on a metal test table using an RF signal generator, an
RF power amplifier, a current injection clamp, and specialized “coupling-decoupling” network (CDN) devices. A
typical test setup for use with L
ON W ORKS devices is shown in Figure 4.9. The test equipment drives a large
common-mode noise voltage onto the twisted pair cable that connects the Auxiliary Equipment (AE) and the
Equipment Under Test (EUT). The AE must be able to continue communicating with the EUT during the test. The
network error rate for this communication should generally be less than 1%, indicating a negligible loss of network
functionality. During the test, the RF signal generator is set to an amplitude modulation (AM) depth of 80%, and
the frequency is slowly swept from 150kHz to 80MHz. Level 2 testing, which represents a “light industrial
environment,” is performed with an injected common-mode voltage on the EUT’s network cable of 3Vrms
(15.3Vp-p including the 80% AM). Level 3 testing, which represents a “harsh industrial environment,” is
performed with an injected common-mode voltage on the EUT’s network cable of 10Vrms (50.9Vp-p including the
80% AM).
The Current Injection method (sometimes called the Bulk Current Injection or BCI method) is the preferred test
method for twisted pair networks. A current clamp is used to inject common mode noise onto the twisted pair
communication cable, and both the AE and the EUT experience similar common mode noise at their network
connections. Because of this, it is generally best if the AE can provide some visual indication of pass/fail during
the test, rather than requiring a wired connection back to a computer to monitor pass/fail. Even when this wiring
passes through a CDN, the RF noise present during the test may disrupt wired communication between the AE and
an external control PC.
A typical setup for EN 61000-4-6 testing of a FT Smart Transceiver-based device and unshielded twisted pair
(UTP) network wire is shown in Figure 4.9.