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General

Connect Allen-Bradley

Reference guide for Allen-Bradley PLC communication (ControlLogix, CompactLogix, SLC 500, MicroLogix).

Proxus supports high-performance communication with Allen-Bradley (Rockwell Automation) controllers using EtherNet/IP (CIP) and PCCC protocols.

Supported Models & Protocol Types

Select the correct ProtocolType matching your hardware generation:

Protocol TypeHardware SeriesConnectionAddressing
AllenBradleyControlLogix, CompactLogixEthernetTag-based
AllenBradleySLCSLC 500, MicroLogixEthernetFile-based (N7:0)
AllenBradleyMicroCipMicro800 SeriesEthernetTag-based
AllenBradleyPcccLegacy via GatewayEthernetFile-based
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Logix Controllers

For modern ControlLogix and CompactLogix, always use AllenBradley. This uses the Native Tag protocol, allowing you to use the same variable names as in Studio 5000.

Connection Parameters

Basic Settings

ParameterTypeRequiredDefaultDescription
HoststringYes-PLC IP Address
PortintNo44818Standard EtherNet/IP Port
PollingIntervalintNo1000Read cycle interval in milliseconds
ConnectTimeoutintNo3000Connection timeout (ms)
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Legacy Ports

Most modern Allen-Bradley PLCs use Port 44818 (EtherNet/IP). However, legacy SLC 5/05 and PLC-5E systems using CSPv4 (PCCC encapsulation) may require Port 2222.

Logix Settings

Applies to AllenBradley

ParameterTypeDefaultDescription
Slotbyte0CPU Slot (usually 0 for CompactLogix)
CipCommandushort0Optional custom CIP command code

SLC/MicroLogix Settings

Applies to AllenBradleySLC

ParameterTypeDefaultDescription
Stationbyte1Local Node/Station ID

Address Syntax (Logix & Micro800)

For AllenBradley and AllenBradleyMicroCip, Proxus uses the Tag Name exactly as defined in the controller.

Examples

TypeAddress ExampleDescription
Base TagProductionCountSimple DINT or REAL tag
Array ElementMotorSpeeds[5]Index 5 of an array
Structure MemberVFD_01.OutputFreqMember of a UDT
Bit in WordStatusWord.3Access bit 3 of an integer
Program TagProgram:MainProg.LocalCounterAccess a program-scoped tag

Address Syntax (SLC & MicroLogix)

For AllenBradleySLC, Proxus uses the classic Logical File addressing format.

Memory Files

File TypePrefixDescriptionExample
OutputOOutput ImageO:0.0 (Word), O:0/0 (Bit)
InputIInput ImageI:0.0 (Word), I:0/0 (Bit)
StatusSProcessor StatusS:1, S:2
BinaryBBit File (B3)B3:0, B3:0/5
TimerTTimer File (T4)T4:0.ACC, T4:0.PRE
CounterCCounter File (C5)C5:0.ACC, C5:0.PRE
IntegerNInteger File (N7)N7:0, N7:100
FloatFFloating Point (F8)F8:0, F8:50
StringSTString FileST:0

Data Types

Proxus TypeAB EquivalentSizeNotes
BoolBOOL1 bit
ShortINT16 bit
UShortUINT16 bit
IntDINT32 bit
UIntUDINT32 bit
LongLINT64 bit
FloatREAL32 bit
DoubleLREAL64 bit
StringSTRINGVariableLogix strings are auto-length

Troubleshooting

ErrorCauseSolution
Connection RefusedPort 44818 blockedCheck firewall and PLC Ethernet port state
Tag Not FoundWrong name or scopeCheck tag is Global or use Program:Scope.Tag
CIP Error 0x01Connection failureGeneral connection error. Check Slot, Path, or Max Connections.
Read Error (SLC)Invalid file numberVerify the file (e.g. N10) exists in RSLogix 500
TimeoutNetwork congestionIncrease ConnectTimeout or reduce PollingInterval

Official Resources

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Need More Help?

For data type issues and byte ordering problems, see Data Type Mismatch and Byte Ordering Issues.

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MicroLogix 1100/1400

Even though these are newer MicroLogix, they still use the AllenBradleySLC protocol (PCCC) rather than the Logix CIP protocol.