Serial Cable Assembly

[DM2]

Is there a standard (military or otherwise) for the construction of a serial cable or more accurately, how to terminate the cable at each end?.  Something on RS232 or RS485?

I was looking through both of my "Serial Port Complete..." books for something that might help me with a technical document I'm writing.  The document is a standard for how to assemble panels.  The panels are based on PLC's.  While most of the assembly is common sense there are industrial standards for such things as grounding, wire size, etc (UL 508A as an example).  I'm trying to provide technical references as to why parts should be assembled in a give way to lend some validity to the document.

We use shielded cable for all of our serial connections.  The cable has a drain wire, and I've always had the panel shop solder the drain wire to the metal DE9 connector.  The thought is that it would aid in draining noise, etc.  I'm not sure how smart this is?  I'm also thinking that we should advise our customers that the drain for the shielded cable they're installing from our equipment to theirs, should be floated at the other end.

[Jan Axelson]

In the RS-485 spec, the guidelines at the end say to connect a shield, if used, to frame ground at either or both ends depending on the application.

The RS-232 spec says pin 1 is to "permit the extension of shield continuity through tandem connectorized sections" and that the DCE should make no connection to pin 1.

Info on the standards:

http://www.lvr.com/serport.htm#standards_and_protocols

Jan