Rockwell Automation 1747-L5xx SLC 500 Modular Hardware Style User Manual User Manual
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Publication 1747-UM011G-EN-P - June 2008
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Selecting Your Hardware Components
DH-485 Protocol - The SLC 500 processors have a DH-485 channel
that supports the DH-485 communication network. This network is a
multi-master, token-passing network protocol capable of supporting
up to 32 devices (nodes). This protocol allows:
•
monitoring data and processor status, along with program
uploading and downloading of any device on the network from
one location.
•
SLC processors to pass data to each other (peer-to-peer
communication).
•
operator interface devices on the network to access data from
any SLC processor on the network.
DF1 full-duplex protocol - DF1 full-duplex protocol (also referred to
as DF1 point-to-point protocol) lets two devices communicate with
each other at the same time. This protocol allows:
•
transmission of information across modems (dial-up, leased line,
radio, or direct cable connections).
•
communication to occur between Allen-Bradley products and
third-party products.
DF1 half-duplex protocol (master and slave) - DF1 half-duplex
protocol provides a multi-drop single master/multiple slave network
capable of supporting up to 255 devices (nodes). This protocol also
provides modem support and is ideal for SCADA (Supervisory Control
and Data Acquisition) applications because of the network capability.
ASCII protocol - The ASCII protocol provides connection to other
ASCII devices, such as bar code readers, weigh scales, serial printers,
and other intelligent devices.
DF1 radio modem protocol - The DF1 radio modem protocol,
optimized for use with radio modem networks, is a hybrid between
DF1 full-duplex protocol and DF1 half-duplex protocol. DF1 radio
modem:
•
supports Store and Forward capability.
•
uses a node address (0...254) on channel 0.
Modbus RTU (Remote Terminal Unit) transmission mode Master protocol -
The Modbus RTU Master protocol provides communication between Modbus
RTU devices through a multi-drop single-master/multiple-slaves network.
This protocol is capable of supporting up to 247 slave devices (nodes).