The Allen-Bradley DF1 Serial OPC Server reads and writes data to
and from various Allen-Bradley controllers using the Allen-Bradley DF1
full-duplex data link protocol on an RS-232-C or RS-422-A asynchronous
link. This Server meets the OPC Data Server Specification Version 2.0.
It also supports OPC Version 1.0.
The Server allows the user to configure bi-directional communications
between its database and the Allen-Bradley controllers. It can be configured
to operate as a true DF1 peer node accepting and performing both read and
write commands from and to other DF1 peers on the network.
The Server supports full peer-to-peer operations including the ability
to be read from and written to. Two types of unsolicited processing are
supported, slave mode unsolicited and device specific unsolicited.
Slave mode unsolicited processing allows both reading and writing operations
by peers to and from the Server. The data written/read is from a common
global database belonging to the Server. All peers exchange data in this
one area. The area acts like a virtual controller’s memory. Device specific
unsolicited processing only allows peers to perform write operations to
a pre-configured Device representing them. The devices in a sense update
their own memory image in the Server. Each peer can write only to its image.
Peers cannot read from the Server nor write to another peer’s image.
The Server has a graphical user interface (GUI) configuration environment
with an "Explorer" look and feel. The configuration environment allows
the Server to be configured with information such as which device to interface
with and which data in those configured devices should be accessed. Once
data points have been configured, the Server can communicate with these
devices on behalf of the Clients. Data exchanged occurs between the Server
and the defined device data locations. These locations are defined
as part of the configuration process generating Tags in the Server database.
Clients and the Server then reference the data via the tag names.
The Server was developed by DASTEC Corporation using the OPC Server
Toolkit from FactorySoft, Inc.
Specifications
Operating System Supported: Windows 95/98/NT/2000 and newer
Device Supported: Any controller supporting the above protocol and functions
can be used with the Server. These include the Allen-Bradley SLC 5/00 through
the 5/05 as well as the MicroLogix family of controllers.
Protocol Supported: DF1 (Full Duplex) to 1770-KF3 or 1747-KE (RS232 to
DH-485 Converters) for multi-drop networking or DF1 point-to-point
Functions Supported: Protected Typed Logical Read with Three Address Fields
for read operations. Protected Typed Logical Write with Three Address Fields
to perform write operations.
Data File Types Supported: Input, Output, Status, Bit, Timer, Counters,
Control, Integer, Float,String and ASCII Data
Data Types Supported: BIT(a single bit), INT2(two bytes as a signed integer),
UINT2(two bytes as a unsigned integer), INT4(four bytes as a signed integer),
UINT4(four bytes as a unsigned integer), BCD3(three digits from two BCD
bytes as a signed integer), BCD4(four digits from two BCD bytes as a signed
integer), FLT4(four bytes as a IEEE floating point), ASCII(single byte
ASCII characters)
Addressing Method: Standard Allen-Bradley SLC addressing: Tf:e.s/b,n
Adjustable Protocol Settings: OPC Server’s DF1 Node Address, Number of
ENQs (1 - 10), Number of NAKs (1 - 10), Link Level Timeout (25 - 5000msec)
Serial Line Control: Selectable control of the following lines: RTS Output,
DTR Output, CTS Input Xmit Control, DSR Input Xmit Control, and DSR Input
Rcv Control