Installation guide

Testing and Maintaining an RIO Network
890 USE 101 00 October 2006 137
On-line and Off-line Error Isolation
Overview RIO troubleshooting is a process of isolating problems in an on-line system, usually
with the aid of LED indicator lamps and system statistics.
Media-related problems are generally solved off-line, not by using LEDs or system
statistics. However, once a problem has been isolated to it’s source using any of the
off-line tests described in the last chapter, it is sometimes possible to locate the
problem source using the on-line troubleshooting procedures discussed below.
For instance, if a network has passed its sweep and TDR tests but has failed its
noise floor test, the network can sometimes be brought up to troubleshoot the
source of the noise. By using the retry counters, the noise source can be isolated
and the problem corrected. Ineffective grounding of external non-Modicon
equipment, ineffective grounding of Modicon equipment, or inadequate spacing of
coaxial from power cable can be isolated while the network is on-line.
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com