Allen-Bradley DF1 Serial Communication Interface API

The DASTEC Corporation Allen-Bradley DF1 Serial Communication Interface API allows the user to implement bi-directional communications to exchange data between applications running on a PC-based or embedded system with other devices supporting the Allen-Bradley DF1 full-duplex serial protocol. The devices can be AB devices, other host computers or even other system applications using the API.

The Allen-Bradley DF1 Serial Communication Interface API enables a system to acts as a client device to other Allen-Bradley peer devices, initiating read and write operations on behalf of the system applications. The API also allows the system to emulate an Allen-Bradley PLC to respond to read and write requests and thus acts as a "virtual PLC" to other AB peers. The API is available for various combinations of operating systems and hardware platforms and can be used with C/C++ or Visual Basic.

The API consists of two component functionalities, client side and server side. The client side functionality is implemented with a single API library. Server side functionality is implemented with a library/executable pair. Together these components manage all aspects of the protocol and data exchange including responding to peers with proper acknowledgements, error/success codes and protocol data byte ordering. The system application need only to deal with the data values exchanged in native byte order. The user can employ either the API's client, server or both functionalities with minimal code implementation.

Client API Functionality

To exchange data with Allen-Bradley peers, a system application can initiate read and/or write operation(s) to the devices by simply calling the client's library functions. The functions include the ability to configure the communication serial port(s), create handle(s) for the device(s) and then using those handle(s) to call the client's library read and write functions. Operation results are returned directly to the calling application, as is data in the case of read operations.

Client API Supports:

Server API Functionality

Using the server executable program provided as part of the API, a system can appear as an Allen-Bradley peer (Allen-Bradley PLC) on the network. By managing all DF1 serial communication operations, the server executable receives and responds to both read and write requests from peer devices. Data written by peers is stored into separate databases maintained by the server executable for each Allen-Bradley file type (Output, Input, Status, Bit, Timer, Counter, Control, Integer, Float, ASCII and String). The data received is stored in the byte order appropriate for the system's processor. The data for read requests received from peers is retrieved and returned from these databases as well.

No user programming is required for the system to act in this server mode. Peers can read and write to the system as if it were an Allen-Bradley PLC with no user application programs running. Applications have access to the server's databases indirectly through specific API library functions calls or directly via shared memory access. In this way, the user applications obtain data written from peers and can update the system's "virtual PLC's" database so that peers can retrieve it.

Server API Supports:

Specifications:

Ordering Information

Product Name:

Allen-Bradley DF1 Serial Communication Interface API

Supported Platforms Part Numbers:

Platform Part Number
Windows NT/2000/XP WinPC-ABDF1API
.NET/.NETCF NET-ABDF1API
Intelligent Instrumentation EDAS CE IIIWinCE-ABDF1API
Intelligent Instrumentation LANpoint CE IIIWinCE-ABDF1API
Linux LINUX-ABDF1API
Contact DASTEC about other supported platforms or to inquire about supporting other platforms.