I have exactly the same problem - how many meters would be appropriate ? I have device A with two RS485 interfaces. One isolated for connection up to 1200m and it is of course telecommunication port. The second not isolated to connect to the device B. Device B is provided with 3m cable (4 wires: 12V power + RS485). In most cases 3m is enough. Do I have specify the max length for this second connection to make it not being the telecommunication port ? If I have, must it be max 10m, or can it be 20m, 25m ?
Best Regards Piotr Galka MicroMade ----- Original Message ----- From: "Steve O'Steen" <[email protected]> To: "John Woodgate" <[email protected]>; <[email protected]> Sent: Thursday, September 10, 2009 6:42 PM Subject: RE: EMC question > What maximum length would be appropriate? Consider if the manufacturer > provided the cable for that particular port but did not limit the cable > length for that port in the Installation Instructions. I would think > this would also satisfy the criteria as long as the provided cable is no > longer than the length identified in the answer to the above question. > > Thanks, > > Steve O'Steen > Director, EMC > Advanced Compliance Solutions, Inc. > [email protected] > 770-831-8048 ext. 210 > www.acstestlab.com > > > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
