Device for determining cable lenth

[RavenJoe]

Does anyone know of an instrument on the market that can be used to determine the lenth of a cable. I have to re-design a PLC remote I/O system and I am limited to 10,000 feet per channel. This is a large sytem and remote racks are very far apart. I need to determine the lenth of my run before I cut the system loose for conversion.
Raven,Joe

 

[xnuke]

Time domain reflectometers (TDR) can measure length of cables. See the following for some basic info:

http://www.tscm.com/riprcop.html

 

[Lewish]

A TDR or "Time Domain Reflectometer" will give you that information, and also any faults in the cable.
Some high-end oscilloscopes have this built in, but you are generally better off with a dedicated instrument.
They are available for rent, or if you know a telephone linesman, you might persuade him to do it for you.
Riser-Bond is one of the leading brands of TDRs.