User manual

Rockwell Automation Publication 1756-UM001O-EN-P - October 2014 103
Serial Communication on 1756-L6x Controllers Chapter 6
Communication with
Serial Devices
When configuring the controller for serial communication, you first specify a
Serial Port mode (System or User), then a protocol.
Figure 18 - Serial Port Mode in the Controller Properties
Table 23 describes the serial communication protocols for use with each mode.
Table 23 - Serial Port Modes, Protocols, and Uses
Mode Protocol Is used to See page
System DF1 Master Control polling and message transmission between the master and slave nodes. 104
DF1 Point to Point • Communicate between the controller and one other DF1-protocol-compatible device.
• Program the controller via the serial port.
105
DF1 Radio Modem • Communication with SLC 500 and MicroLogix™ 1500 controllers.
• This protocol supports master/slave and store/forward configurations.
106
DF1 Slave Configure the controller as a slave station in a master/slave serial communication network. 109
DH-485 Communication with other DH-485 devices via a multi-master and token-passing network that enables
programming and peer-to-peer messaging.
110
User ASCII • Communicate with ASCII devices.
• Use ASCII instructions to read and write data from and to an ASCII device.
112