The CDN-T8SE is used during conducted emissions or immunity tests on devices with signal/telecom ports intended for connection to shielded (or screened) lines with up to four balanced pairs. The EUT and AE ports of the CDN-T8SE are equipped with shielded RJ45 receptacles. The RF input/output port is located on the top side of the network, and is fitted with a female BNC type connector. The outer surface of the network’s metallic enclosure is powder coated for durability, and is mounted onto an untreated (conductive), stainless steel base plate. The base plate extends beyond the footprint of the network enclosure at the front and back, providing convenient access to effectively ground the network, which is essential.
Any individual Com-Power CDN may be purchased separately, or as part of a CIS series conducted immunity test system. Test systems also include an ACS series power amplifier, as well as the required accessories.
Flexibility
The CDN-T8SE could be referred to as a “dual-threat” network, as it can be used either as a CDN for conducted immunity testing per IEC 61000-4-6, or as an ISN for conducted emissions testing per CISPR 22/32. It meets all applicable requirements of these standards for each test, as well as those contained within CISPR 16-1-2.
Conducted Immunity Systems
Any individual Com-Power CDN may be purchased separately, or as part of a CIS series Test System. Test systems also include an ACS series power amplifier (25W, 50W or 100W), directional coupler, power attenuators, two 150Ω to 50Ω adapters, 50Ω termination, common-mode adapters, cables and automation software.
Calibration
The CDN-T8SE is individually calibrated for all necessary performance parameters with NIST traceability. The calibration data and certificate is shipped with each network. Recognized ISO 17025 accredited calibration is also available upon request.
Application
The CDN-T8SE is suitable for conducted emissions and immunity tests on signal/telecom ports (such as ethernet) intended for connection to shielded (Cat. 3 or Cat. 5) lines containing up to four balanced pairs. During emissions testing, an ISN provides:
- a means by which to measure spurious common-mode noise from the EUT, present on the line under test
- common-mode isolation between the EUT and AE, minimizing the affects that any spurious noise generated by the AE may have on the measurement.
Conversely, CDNs provide what are essentially the same functions during immunity testing, but from the opposite perspective:
- a means of coupling RF common mode signals on to the line(s) under test of the EUT
- common mode isolation between the EUT and AE, minimizing AE exposure to the injected RF test signal.
Prior to the immunity test, CDN drive levels must be established, which is typically done via software control. At each test frequency, the RF voltage applied to the CDN is adjusted incrementally until the appropriate voltage (Umr) is measured at the output of the 50Ω to 150Ω adapter (ADA-515-2), which is connected to the common mode (shorting) adapter attached to the EUT port. It is important to note that test levels given in the IEC 61000-4-6 standard correspond to the equivalent open circuit voltage (Uo), and should not to be confused with the actual voltage level measured during the above process (Umr). The relationship between Uo and Umr is:
Umr (Vrms) = Uo (Vrms) / 6 & Umr (dBμV) = Uo (dBμV) - 15.6 dB