60601-1-2 ME Equipment sub system definition

[blazin912]

6.1.1.2 Tests

CISPR test methods shall be used, with the clarifications and exceptions specified in a), b), and c) below.

b) * Subsystems

Compliance with the requirements of CISPR 11 may be demonstrated by testing each subsystem of an ME SYSTEM, provided that normal operating conditions are simulated.

When ME EQUIPMENT is being evaluated that interacts with other equipment to form an ME SYSTEM, then the evaluation may be carried out using either additional equipment to represent the total ME SYSTEM or with the use of simulators.

In regards to this test, we have a ME system that has external ports. Usb, Ethernet, VGA. The external video port allows the final location to attach an external monitor to the ME System to display the video on an ADDITIONAL display other than the display associated with the ME System we provide.

The problem is, we do not provide a second monitor. So, do we need to attach a monitor to this VGA port to perform EMC?

In my experience this would mean any monitor other than the one utilized would fall into the category of IFU statements saying, "Any use of this equipment in ways other than those described in this document/testing configuration may result in EMC compliance issues."

How does one handle this situation? Wouldn't this be similar to having a USB port that allows the user to attach/supply their own USB Hub, Thumbdrive, Keyboard, Mouse.. whatever. You can show you have a port but you can't show what's attached in every possible configuration.

 

[Pads38]

I might suggest that you could have different set-ups for the emissions tests and the immunity tests.

For the emissions use a "dummy monitor" - connect using your specified length of video lead to 75 ohm terminations of the video lines.

For immunity connect a monitor to ensure that the signal continues to be usable. For the RF radiated immunity test the monitor would be outside the anechoic chamber with, probably, lots of ferrites on the video lead so as to restrict the exposure to just your equipment under test.

But, hopefully, you can discuss this with your test house. They are usually able to provide some ideas, ideally well in advance of "test day". If they cannot / will not offer advise then perhaps you are using the wrong test house!