Installation guide

Glossary
890 USE 101 00 October 2006 153
pull strength The maximum allowable torque that may be used to pull a cable through a conduit
or enclosure.
redundant cable An RIO network topology in which two cable systems are run from the RIO
processor in a PLC to the same group of drop adapter nodes. A dual cable topology
requires dual RIO comm ports in the RIO processor node and in all the adapters.
See also dual cable.
redundant
programmable
control
See Hot Standby System.
remote I/O drop
adapter
A node at each remote drop that connects to the coaxial cable system, processes
messages from the remote I/O processor, and updates the I/O at the drop. See also
node.
remote I/O head
processor
The master node for the RIO network; it processes commands for the PLC, and it
sends messages to/receives messages from the adapter nodes on the network.
repeater A device that consists of a transmitter and receiver or transceiver, used to amplify a
signal to increase signal length.
response
window
A finite waiting time from transmission to an expected reply, preventing the system
from being locked out by a nonreplying node.
retransmission The resending of a message because transmission error in the message-generating
node or a failure to receive the message at a receptor node.
retry See retransmission.
retry count The number of times the RIO processor has had to retransmit a message.
return loss The amount of signal reflected back toward the signal origin, expressed in dB down
from the original signal. Return loss is caused by impedance mismatch; the high the
return loss, the better.
RFI (radio
frequency
interference)
Noise caused by another transmitting device.
R
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com