DF-1 / DF1 protocol is an
asynchronous
Asynchrony is the state of not being in synchronization.
Asynchrony or asynchronous may refer to:
Electronics and computing
* Asynchrony (computer programming), the occurrence of events independent of the main program flow, and ways to deal with ...
byte-oriented protocol that is used to communicate with most
Allen Bradley RS-232
In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such a ...
interface modules. DF1 protocol consists of link layer and application layer formats. DF1 works over half duplex and full duplex modes of communication.
Application layer messages
Application layer message format consists of ''Command Initiator messages'' (request messages) and ''Command Executor'' (reply messages). Important command initiator messages are as follows.
* apply port configuration
* bit write
* change mode
* close file
* diagnostic status
* disable forces
* disable outputs
* download request
* echo
* enable outputs
* enable PLC scanning
* enter download mode
* enter upload mode
* exit download/upload mode
* file read
* file write
* get edit resource
* initialize memory
* modify PLC-2 compatibility file
* open file
* physical read
* physical write
* read bytes physical
* read diagnostic counters
* reset diagnostic counters
* read link parameters
* read-modify-write
* read section size
* restart request
* set CPU mode
* set data table size
* set ENQs
* set link parameters
* set NAKs
* set timeout
* set variables
* shutdown
See also
*
Computer network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
ing
*
Computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
External links
DF1 Protocol Reference ManualDF1 protocol Open Source
{{Automation protocols
Industrial computing
Serial buses
Industrial automation