TOP Server for Allen Bradley ControlLogix Ethernet Driver
Usage with ControlLogix Gateway to Downstream Devices

The TOP Server ControlLogix driver has supports full gateway operation through your ControlLogix rack to downstream DH+ and ControlNet networks. This application note shows you what you can do with the TOP Server and ControlLogix Gateways and how to configure the driver Device ID to route to downstream nodes. This application note assumes you are already familiar with how to do the basic setup of Devices in the TOP server. If you are not familiar with that we suggest you watch our online introductory training video or read our Getting Started Guide.

Overview (click to jump straight to Examples)

The concept behind routing is to provide a means of communicating with a remote ControlLogix backplane over various networks. Routing can be thought of as a bridge between your local ControlLogix backplane and a remote ControlLogix backplane even if they are on two different fieldbus networks. Access to a remote (destination) backplane allows for direct communication with the following modules located on this backplane:

Remote Modules Accessible Via Routing:

• ControlLogix 5000 family processors (i.e. L5550, L5555) for ControlLogix applications
• 1756-DHRIO interface module for DH+ Gateway applications
• 1756-CNB or 1756-CNBR interface module for ControlNet Gateway applications

A routing path is a series of backplane hops, with the last hop pointing to the destination backplane. Each hop requires a ControlLogix backplane (not a ControlLogix processor). An individual hop can utilize one of the following networks as its medium:

Networks Supported:

1. ControlNet
2. DH+
3. Ethernet (EtherNet/IP)

Application Notes

1. Messages cannot be routed in or out of the same interface module channel more than once within the path. Doing so results in CIP Error 0x01 Ext. Error 0x100B.
2. For multiple channel interface modules, messages cannot be routed into and then immediately out of that same module (using different channels), regardless if the message is directed to the backplane first or avoids the backplane all together. As previously mentioned, the latter is not supported since each hop requires a ControlLogix backplane. An example would be to route a DH+ message from one DH+ link (ie. Channel A of 1756-DHRIO) to another DH+ link (ie. Channel B of same 1756-DHRIO) through one 1756-DHRIO interface module This is commonly referred to as Remote DH+ messaging and is not supported.

Connection Path Specification

The routing path is specified in the Device ID when you configure the Device in the TOP Server. As with non-routing applications, communication originates from the ControlLogix Ethernet driver on the PC and is directed at the local ControlLogix Ethernet Interface (1756-ENET or 1756-ENBT). Once at this local 1756-ENET, the Device ID specifies a way out of the module and onto the backplane, just like with non-routing applications. From there the routing path will direct the message to the desired ControlLogix backplane. The remainder of the Device ID will determine what device to communicate with (ControlLogix processor, DH+ node, ControlNet node). The routing path specification begins and ends with the left and right bracket respectively ([, ]). The path itself is a series of port/link address pairs, identical to the Communication Path syntax in RSLogix 5000 Message Configuration dialog. A port describes a way out of a device via a network or backplane. A link address is a destination address and is commonly referred to as a node id or next hop.

Designator Description Formats Valid Values Port ID Specifies a way out of the interface module in question. See Ports below. Decimal 0 - 65535 Link Address If the corresponding port is the backplane, then the link address is the slot number of the interface module you wish to go out of. Decimal 0 - 255   If the corresponding port is an interface module port, then the link address specifies a destination node as follows. - DH+/ControlNet: node id -1756-ENET module: IP address.

The general syntax for the connection path to enter in the Device ID field in the TOP Server Device Properties dialog is shown in bold below.

Single Hop
IP Address,Port ID0, [Link Address0, Port ID1, Link Address1, Port ID2], Link Address2

Multi-Hop (N Hops)
IP Address,Port ID0, [Link Address0, Port ID1, Link Address1, Port ID2, Link Address2, ... Port ID(N+1), Link Address(N+1), Port ID(N+2)], Link Address(N+2)

Note: The last Port ID in the path (Port ID2 and Port ID(N+2) for single hop and multi-hop respectively) must be 1 (port for backplane).

The Port ID0 must be 1 (port for backplane), Link Address2 and Link Address(N+2) are the slot numbers of the remote Logix processor/1756-DHRIO module/1756-CNB module.

Ports

Interface Module Port 1 Port 2 Port 3 1756-ENET & ENBT Modules Backplane Ethernet Network N/A 1756-DHRIO Backplane DH+ Network on Ch. A DH+ Network on Ch. B 1756-CNB Backplane ControlNet Network N/A

Examples

Due to the complex nature of this feature, examples may be the best tutorial. Note in the examples below we have included L5550 processors in the rack. You do NOT have to have a processor in a ControlLogix rack in order to have it operating as a Gateway.  We just included them because one of our examples includes routing through a ControlLogix Gateway to downstream ControlLogix L555x processors. Lastly, although the drawing does not show it, we do support both the 1756-ENET and ENBT Ethernet cards and the L5555 processors.

The examples below will include the entire the Device ID minus the IP of the local 1756-ENET. Again, the perspective of the Device ID/Routing Path is from the local 1756-ENET module. Hop descriptions are in the form: Link Address(N), Port ID(N+1), Link Address(N+1), Port ID(N+2). See Connection Path Specification above for help. For further details on building a connection/routing path, refer to Allen-Bradley Publication 1756-6.5.14, pp. 4-5 through 4-8.

Key to colors in picture below:
Green = Ethernet
Blue = DH+
Orange = ControlNet

Example 1) Logix5550 to PLC-5 via DH+ Gateway

Destination Node Model Routing Device ID less IP PLC-5/20 (D) DH+ Gateway No 1,1.B.9

Example 2) Logix5550 to PLC-5C via CN Gateway.

Destination Node Model Routing Device ID less IP PLC-5/40C (B) CN Gateway No 1,2.A.1

Example 3) Logix5550 to Logix5550 via Routing over DH+.

Destination Node Model Routing Device ID less IP Logix5550 (C) ControlLogix 5550 Yes 1,[1,2,8,1],0

Routing Path Breakdown

Hop Segment Description 1 1,2,8,1 Slot 1 (DHRIO) -> Port 2 (DH+ Ch A) -> DH+ Node 8 -> Logix C Backplane

Example 4) Logix5550 to PLC-5C via CN Gateway, Routing over DH+.

Destination Node Model Routing Device ID less IP PLC-5/80C (E) CN Gateway Yes 1,[1,2,8,1],2.A.3

Routing Path Breakdown

Hop Segment Description 1 1,2,8,1 Slot 1 (DHRIO) -> Port 2 (DH+ Ch A) -> DH+ Node 8 -> Logix C Backplane

Example 5) Logix5550 to Logix5550 via Routing over DH+, ControlNet.

Destination Node Model Routing Device ID less IP Logix5550 (F) ControlLogix 5550 Yes 1,[1,2,8,1,2,2,15,1],0

Routing Path Breakdown

Hop Segment Description 1 1,2,8,1 Slot 1 (DHRIO) -> Port 2 (DH+ Ch A) -> DH+ Node 8 -> Logix C Backplane 2 2,2,15,1 Slot 2 (CNB) -> Port 2 (CN Ch A) -> CN Node 15 -> Logix F Backplane

Example 6) Logix5550 to SLC 5/04 via Routing over DH+, ControlNet.

Destination Node Model Routing Device ID less IP SLC 5/04 (G) DH+ Gateway Yes 1,[1,2,8,1,2,2,15,1],1.A.2

Routing Path Breakdown

Hop Segment Description 1 1,2,8,1 Slot 1 (DHRIO) -> Port 2 (DH+ Ch A) -> DH+ Node 8 -> Logix C Backplane 2 2,2,15,1 Slot 2 (CNB) -> Port 2 (CN Ch A) -> CN Node 15 -> Logix F Backplane

Example 7) Logix5550 to Logix5550 via Routing over DH+, ControlNet, Ethernet.

Destination Node Model Routing Device ID less IP Logix5550 (G) ControlLogix 5550 Yes 1,[1,2,8,1,2,2,15,1,3,2,192.192.180.101,1],0

Routing Path Breakdown

Hop Segment Description 1 1,2,8,1 Slot 1 (DHRIO) -> Port 2 (DH+ Ch A) -> DH+ Node 8 -> Logix C Backplane 2 2,2,15,1 Slot 2 (CNB) -> Port 2 (CN Ch A) -> CN Node 15 -> Logix F Backplane 3 3,2,192.192.180.101,1 Slot 3 (ENET) -> Port 2 -> Remote1756-ENET IP -> Logix H Backplane