Ask an Expert: DCS System Log and Quantum I/O Network Errors

PUBLISHED ON Jul 06, 2010

by Milt Beebe, Preventative Maintenance Expert

Q: Does your DCS system log show Quantum I/O network errors? How do you know if your Quantum (S908) network is working correctly?

A: S908 network cables and taps, as any other physical network, are subject to the environmental hazards which may be present: animals, sunlight, water, corrosives, extreme high and low temperatures.  NovaTech Automation recommends the health and condition should be certified at installation and routinely checked (3- 5 years) with a high-resolution MTDR (Metallic Time Domain Reflectometer).

Hand held testers used for Ethernet testing do not do a good job testing S908 cabling systems, despite the fact that most of them have BNC connectors and claim they are good for coaxial cable testing. Each copper segment must be tested. Testing several copper segments connected by taps, splices, or couplers does not yield meaningful results.

S908 segment analysis can find, document, and restore a network segment such as shown in the above “before” and “after”  TDR charts.

In addition, the network check should include a physical check of each drop cable, trunk cable, and tap to ensure the cables are properly supported, and do not exceed minimum bend radius (20 times the cable diameter).

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