A-B Ethernet Communications

ORMEC’s MotionBASIC® Extension (MBX) for Allen-Bradley Ethernet communications adds to the network capability of the ORION® controller. A-B Ethernet provides a fast and low cost method to send and receive application data between controllers on an Ethernet network using A-B Ethernet communications. The MBX adds MotionBASIC® statements that make it simple to use Ethernet to communicate between ORION® controllers, Allen-Bradley PLCs and PCs running popular HMI packages.

Features and Benefits
Using the A-B Ethernet MBX as a communication method provides a number of key advantages:

• Interface an ORION® controller directly to SLC-5/05 PLCs and PLC5 family PLCs that support Ethernet.
• Connect an ORION® controller to popular HMI packages that use A-B Ethernet to transfer of integers and floating point variables as object tags for operator input and output.
• Using standard Ethernet cards provides a low cost physical interface to the ORION® controller.
• Based on standard Internet technologies ... TCP/IP protocol is layered on high speed 10base Ethernet networks.
• Enhances the flexibility and performance of message transfers by allowing peer-to-peer connections between network nodes.

Overview
The A-B Ethernet MBX extends the MotionBASIC® operating system to provide connectivity between ORION® controllers, Allen-Bradley PLCs and PCs running popular HMI packages by using A-B Ethernet communications. An ORION® controller with an Ethernet link installed and configured with the A-B Ethernet MBX, can open an A-B connection to send application data to any A-B server node on the network. The ORION® controller also has the ability to start a server node that will accept any connection from another A-B node and receive application data.

Multi-protocol capability
Software development for a system with multiple ORION® controllers using the full capabilities of A-B communications can now be performed with one PC. Since Ethernet is a multiprotocol network, any PC connected to the network can establish a TCP/IP connection, communicate to an ORION® and run the MotionDesk for program development over the same wire at basically the same time A-B communications are also going on.

A-B Ethernet Architecture
ORION® A-B Ethernet consists of a physical layer based on 10baseT, 10base2, or 10base5 type Ethernet communication standards along with a client/server transport protocol (TCP/IP stack) to provide reliable peer-to-peer communications in the ORION® controller. At the application level the MBX-ABE uses a protocol developed for PLC networking to transfer register data as messages between controllers. All transfers happen as a background task concurrent with the user’s main application program.

User access at the application programming interface level consists of MotionBASIC® extensions for making the connection to the destination server and the specifying source and destination registers for a read or a write multiple register transfer to that connected server. Concurrent multiple connections can be made to multiple servers on the network for a flexible and efficient arrangement for updating application data between a variety of system components.

For constructing messages, the ORMEC includes MotionBASIC® mapping methods (MBX-MAP) to simplify data organization at the PLC register level for the user.

ORION® Variable Mapping
MBX-MAP extends the capability of MotionBASIC® by providing a method to map PLC register values to any MotionBASIC® variable in the controller. Typically, PLC registers are addressed numerically but MotionBASIC® uses symbolic labels to address variables. With mapping the MotionBASIC® variable’s symbolic label can be simultaneously defined as a PLC register address value. Register mapping values can range from 0 to 32367. The main purpose of this mapping feature is to allow the MBX to quickly assemble the content of various variables such as integers, and floats that reside in different areas of the controller’s memory, into an ordered list of data and transferred over the network as one message.

MBX-MAP also provides the ability to monitor the changes in selected variables. Any change in the data contained in the variable selected, can result in an event interrupt. The event interrupt, if enabled, will in execute a user defined subroutine designed to respond to the changes in the data as a result of receiving the message.

A partial list of PLCs, popular Human Machine Interface (HMI) packages and OCX software controls that can communicate with an ORION controller incorporating the A-B Ethernet MBX.

• PLCs: Allen-Bradley SLC-5/05 PLCs and PLC5s that support Ethernet communications
• HMI Packages: RsView32 by Rockwell Automation, InTouch by Wonderware, Fix by Intellution, FactoryLink by U.S. Data and Citect by CI Technologies
• OCX Software Controls: ASABETHERNET an OCX by Automation Solutions, ABEther an OCX by Parijat, Inc.,  IN-GEAR 32 an OCX by CimQuest, Inc.

A-B Ethernet MotionBASIC® Extensions

MBX-ABE Statements

• ABE.OPEN <device%>,"IP_address,PLC5" Open client connection to a PLC5 server.
• ABE.OPEN <device%>,"IP_address,SLC" Open client connection to a SLC-505 server.
• ABE.OPEN <device%>,"IP_address,server" Open server connection to accept PLC5 or SLC.
• ABE.READ [qty of reg(s)] FROM <starting src_register> TO <starting dest_register>
• ABE.WRITE [qty of reg(s)] FROM <starting src_register> TO <starting dest_register>
• ABE.CLOSE [<device%>] Close one connection or all connections.

MBX-ABE Control functions and access variables

• ABE@ = ON Set mapped register access enabled.
• ABE.SOCKOPEN@(device%) Get status of TCP/IP connection.
• ABE.DEST@ = device% Set destination connection for next client command.
• ABE.MSG@(device%) Get client reply received status.
• ABE.LED@ = <led value> Set MBX-ABE to use the front panel MB LED indicator.
• ABE.CTR@(ctr%) Get 1 of 32 error status counts of client and server connection activity during data transfers.
• ABE.STS@(device%) Get the response code for last exception that occurred.

Diagnostic Commands that display to the Direct Mode window in MotionDesk

• ABE.TRACE@= ON Enable real-time display of message transfer activity.
• ABE.DUMP Display the current settings and information for all current connections.
• PING <IP address> Check to make sure that the destination IP address is available and listening on the network.

MBX-MAP MotionBASIC® Mapping Statements

• MAP <regnum> TO <variable> Relate a register number 0 to 32767 to a MotionBASIC® variable name.
• ON EVENT MAP@(regnum) GOSUB [label]    Call subroutine when value mapped to regnum changed.

Allen-Bradley, PLC5 and SLC are trademarks of Rockwell Automation Inc.

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