A Next Generation OCS

OCS connectivity to

(aka the Evil Empire)

RockwellAutomation

A Next Generation OCS

What if I want more than an Ethernet/IP I/O Connection and its 256 Byte limit?• There are several options for communicating

with A-B products• DF1 full duplex serial is available as a

downloadable serial protocol• With an affordable external device, Allen-Bradley

Ethernet and Ethernet/IP are also an option

A-B Connectivity

A Next Generation OCS

PCCC & CIP are the two Protocol families supported by Rockwell

• What is PCCC?• It is the application layer message packet of

DF1• It allows you to issue poll/response messages

to arrays of A-B data (register/table/file)• It is the core message that moves easily

between DF1, DH485, DH+, AB/Ethernet & Ethernet/IP with PCCC encapsulation

• What is CIP?• As discussed - Common Industrial Protocol• Used in ControlLogix & CompactLogix CPUs• It is Object Oriented - services are sent to

specific instances of objects. It is not based on accessing arrays of file data.

A-B Protocol Families

A Next Generation OCS

A summary of A-B protocols existing over a variety of media

• RS-232• DF1 Full Duplex. The core protocol spoken by

most A-B PLCs. Is proprietary but published.• DF1 Half Duplex. Very slow and rarely used.• DF1 Radio. Recently added in approx. 2003.• DF1 to Logix CPU. Encapsulates fragmented

CIP messages within DF1. Not documented.• RS-485

• DH485. A proprietary (closed), token passing network allowing slaves to talk directly to one another. Does not work over Ethernet or radio due to token speed. Some 3rd parties attempt to support it in a “single master” mode - which often doesn’t work.

A-B Protocols

A Next Generation OCS

A summary of A-B protocols existing over a variety of media

• Ethernet• AB/Ethernet. Sometimes called CSP. An older

TCP port 2222 protocol from the PLC5E. Very closely related to DF1 & DH+. Only works on non-CIP messaging. A-B would like to obsolete it.

• Ethernet/IP. Can move CIP or even DF1 encapsulated messages. In its non-encapsulated form is object based and not register/table/file based like DF1.

• Others• DH, DH+. Older, proprietary token bus

systems. NOT RS-485 based, but requires custom hardware. A-B wants to move these users over to ControlNet.

A-B Protocols

A Next Generation OCS

• Directly supported through OCS Downloadable Protocol• Lowest Cost• Works with virtually all A-B PLCs• Good solution for MicroLogix, SLC

OCS Connectivity to A-B

MicroLogix

XLe OCS

SLC 5

NX OCS

DF1 Protocol Dialog

DF1 Serial

A Next Generation OCS

ControlLogixCompactLogix

• Indirectly supported - requires an economical gateway solution (IAP Gateway)• Connection at OCS end can be either

serial OR Ethernet

OCS Connectivity to A-BA-B/Ethernet

LX OCS

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IAP Gateway

SLC 5/05 PLC-5E

AB/EthernetDF1 RS-232

A Next Generation OCS

ControlLogix

CompactLogix

• IAP Gateway re-configures and re-routes Modbus/TCP messages to/from A-B PLC via Ethernet/IP

• A-B PLC responds to traffic as if it were coming from another A-B product

OCS Connectivity to A-BEthernet/IP (non CIP based)

QX OCS

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IAP Gateway

Modbus/TCP Ethernet/IP