Installation guide

Testing and Maintaining an RIO Network
134
890 USE 101 00 October 2006
RIO System
Tests for Critical
Applications
Tests 8 ... 10 guarantee performance—if your RIO network is critical to the operation
of your process, these tests are highly recommended. They can also be beneficial if
your operating environment is extremely noisy.
Test 8 Attenuation Measurements
Taken during the attenuation sweep test or using the LMT/LMR attenuation
measurement system. This test yields the maximum attenuation on the trunk and on
the entire network, end to end. The attenuation should be close to the designed
attenuation and must never exceed 35 dB (32 dB for the host-based PLCs).
Test 9 Return Loss Sweep Test
A test of reflections on the network. It tests the trunk cable at all end points and at
least one drop cable for return loss over the full RIO bandwidth. The return loss on
the trunk must be below 16 dB, and below 14 dB on any drop.
Test 10 Noise Floor Level Test
Determines the level of noise on the network within the full bandwidth used by RIO.
Ensures that the noise floor level is below +10 dBmV over the full RIO bandwidth at
any trunk end point and at least one drop cable.
Network Setup The last test should be performed on all startups.
Test 11 Network Startup
Tests all the nodes on the network while they are communicating. Communication
error counters are monitored over a given time period.
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com