Echelon FT 3150 Smart Transceiver - Manual (Page 110)

Chapter 4 - Hardware Design Considerations
104 FT 3120 / FT 3150 Smart Transceiver Data Book
When the network data line extends outside of a building or grounded structure, every FTT-10A and FT 3120 / 3150
Free Topology FT Smart Transceiver-based device on the network segment, whether located indoors or outdoors,
must be equipped with surge protection circuitry. Additionally, protection devices must be added to the network at
every point where the network cable exits the building or structure.
EN 61000-4 Electromagnetic Compatibility (EMC)
Testing
Echelon has tested the FT Smart Transceivers operating in typical two-layer application boards to verify that they
comply with the five applicable EN 61000-4 test requirements (formerly known as IEC 1000-4 tests). Provided that a
device's PCB is designed following the guidelines in this chapter, the FT Smart Transceivers should pass the EN
61000-4 tests to the levels described in Table 4.2.
Table 4.2 EN 61000-4 Test Immunity Levels
EN 61000-4-2 ESD testing is performed on a metal test table using an ESD transient generator. Level 4 testing
involves injecting up to ±8kV contact discharges and up to ±15kV air discharges into the product under test.
Depending upon the product design, discharges may be injected at the network connector, power connector and other
user-accessible areas. During the test, proper device operation should continue with occasional loss of a packet due
to the ESD hits.
EN 61000-4-3 RF Susceptibility testing is generally performed in an RF-shielded anechoic chamber. The product
under test is placed on a non-conducting table in the chamber, and antennas are used to subject the product to intense
radio frequency fields. Under the test, proper operation continues with the occasional loss of a packet. Level 2 testing
is performed with a field of 3V/m, which is classified by the test standard as a ‘moderate electromagnetic radiation
environment.’ Level 3 testing is performed with a field of 10V/m, which is classified by the standard as a ‘severe
electromagnetic radiation environment.’
EN 61000-4-4 Burst testing is performed on a non-conducting table, with 1 meter of the network cable clamped in a
high-voltage burst generation apparatus. Under the test, proper operation continues with occasional loss of a packet.
There are three bursts injected onto the network cable each second. Level 3 testing is performed with ±1kV bursts,
which are classified by the test standard as representative of a ‘typical industrial environment.’ Level 4 testing is
performed with ±2kV bursts, which are representative of a ‘severe industrial environment.’
EN 61000-4-5 Surge testing is performed on a non-conducting table using specialized surge generation equipment.
The surges are injected directly into the network wiring via a coupling circuit. See Figure 10 of EN 61000-4-5
(formerly Figure 11 of IEC 801-5). Under the test, proper operation continues with the occasional loss of a packet.
Level 2 testing is performed with up to ±1kV surges, and Level 3 testing is performed with up to ±2kV surges. Level
“X” testing is performed at a user-defined surge voltage (6kV in the case of the FT Smart Transceivers).
EN Test Description FT Smart Transceiver Immunity Level
EN 61000-4-2 ESD Immunity Level 4
EN 61000-4-3 Radiated Susceptibility Level 3
EN 61000-4-4 Burst Immunity Level 4
EN 61000-4-5 Surge Immunity Level 3 (2kV) with D3-D6 =
BAV-99-equiv. diodes in Figure 4.1
Level “X” (6kV) with D3-D6 =
1N4935-equiv. diodes in Figure 4.1
EN 61000-4-6 Conducted RF Immunity Level 3 (C5 =C6 = 56pF caps required)