Allen-Bradley 1756-L63XT, Руководство пользователя

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Rockwell Automation Publication 1756-UM001O-EN-P - October 2014 109
Serial Communication on 1756-L6x Controllers Chapter 6
DF1 Slave Protocol With the DF1 slave protocol, a controller uses DF1 half-duplex protocol. One
node is designated as the master and it controls who has access to the link. The
other nodes are slave stations and must wait for permission from the master
before transmitting.
Make these considerations when using the DF1 Slave protocol:
• If multiple slave stations are used on the network, link slave stations by
using modems or line drivers to the master.
• If you are using one slave station on the network, you do not need a
modem to connect the slave station to the master.
• Control parameters can be configured without handshaking.
• 2…255 nodes can be connected to one link.