Publication 20D-UM002C-EN-P - November 2003
9-6 Communicating with Devices on a Serial Link
DF1 master mode control of polling and message transmission between the master and slave nodes.
The master/slave network includes one controller configured as the master node and as
many as 254 slave nodes. Link slave nodes using modems or line drivers.
A master/slave network can have node numbers from 0-254. Each node must have a
unique node address. Also, at least 2 nodes must exist to define your link as a network
(1 master and 1 slave station are the two nodes).
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DF1 slave mode using a controller as a slave station in a master/slave serial communication network.
When there are multiple slave stations on the network, link slave stations using
modems or line drivers. When you have a single slave station on the network, you do
not need a modem to connect the slave station to the master; you can configure the
control parameters for no handshaking. You can connect 2-255 nodes to a single link. In
DF1 slave mode, a controller uses DF1 half-duplex protocol.
One node is designated as the master and it controls who has access to the link. All the
other nodes are slave stations and must wait for permission from the master before
transmitting.
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User mode communicating with ASCII devices
This requires your program logic to use the ASCII instructions to read and write data
from and to an ASCII device.
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Use this mode: For: See page:
