Allen-Bradley micrologix 1500, Руководство пользователя

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1 Publication 1764-UM001A-US-P
Appendix
E
Understanding Communication Protocols
Use the information in this appendix to understand the differences in
communication protocols. The following protocols are supported from the RS-232
communication channel:
•
DF1 Full-Duplex
•
DF1 Half-Duplex Slave
•
DH-485
•
Modbus RTU Slave (1764-LSP and 1764-LRP Series B Processors only)
•
ASCII (1764-LSP and 1764-LRP Series B Processors only)
See Communication Connections on page 4-1 for information about required
network devices and accessories.
RS-232 Communication
Interface
The communications port on the MicroLogix 1500 utilizes an RS-232 interface.
RS-232 is an Electronics Industries Association (EIA) standard that specifies the
electrical characteristics for serial binary communication. It provides you with a
variety of system configuration possibilities. (RS-232 defines electrical
characteristics; it is
not a protocol.)
One of the biggest benefits of an RS-232 interface is that it lets you easily integrate
telephone and radio modems into your control system.
DF1 Full-Duplex
Protocol
DF1 Full-Duplex protocol is an open protocol developed by Allen-Bradley. It
provides a point-to-point connection between two devices. DF1 Full-Duplex
protocol combines data transparency (American National Standards Institute ANSI
- X3.28-1976 specification subcategory D1) and 2-way simultaneous transmission
with embedded responses (subcategory F1).
MicroLogix 1500 controllers support the DF1 Full-Duplex protocol via RS-232
connection to external devices such as computers, controllers, and other interface
devices that support DF1 Full-Duplex.
DF1 is an open protocol. Refer to DF1 Protocol and Command Set Reference
Manual , publication 1770-6.5.16, for more information.
AB Spares