Specifications

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Allen-Bradley ControlLogix Ethernet Driver Help

N7:0 Word 0

N7/26 Bit 26

N12:4/15 Bit 15 word 4

N7:10 [8] 8 element array starting at word 10

N15:0 [4] [5] 4 by 5 element array starting at word 0

Float Files

To access float files, specify a file number and an element. The default data types are shown in bold.

Syntax Data Type Access

F<file>:<element> Float Read/Write

F<file>:<element> [rows][cols] Float (array type) Read/Write

F<file>:<element> [cols] Float (array type) Read/Write

The number of array elements (in bytes) cannot exceed the block request size specified. This means that array

size cannot exceed 8 floats given a block request size of 32 bytes.

Ranges

PLC Model File Number Max. Word

MicroLogix 8-999 999

SLC 500 Fixed I/O NA NA

SLC 500 Modular I/O 8-999 999

PLC-5 Series 3-999 1999

Examples

Example Description

F8:0 Float 0

F8:10 [16] 16 element array starting at word 10

F15:0 [4] [4] 16 element array starting at word 0

ASCII Files

To access ASCII file data, specify a file number and a character location. The default data types are shown in

bold.

Syntax Data Type Access

A<file>:<char> Char, Byte* Read/Write

A<file>:<char> [rows][cols] Char, Byte* Read/Write

A<file>:<char> [cols] Char, Byte* Read/Write

A<file>:<word offset>/length String** Read/Write

*The number of array elements cannot exceed the block request size specified. Internally, the PLC packs two

characters per word in the file, with the high byte containing the first character and the low byte containing the

second character. The PLC programming software allows access at the word level or two-character level. The

Allen-Bradley ControlLogix Ethernet Driver allows accessing to the character level.

Using the programming software, "A10:0 = AB," would result in 'A' being stored in the high byte of A10:0 and 'B'

being stored in the low byte. Using the Allen-Bradley ControlLogix Ethernet Driver, two assignments would be

made: "A10:0 = A" and "A10:1 = B." This would result in the same data being stored in the PLC memory.

**Referencing this file as string data allows access to data at word boundaries like the programming software.

The length can be up to 232 characters. If a string that is sent to the device is smaller in length than the length

specified by the address, the driver null terminates the string before sending it down to the controller.

Ranges

PLC Model File Number Max. Character

MicroLogix 3-255 511

SLC 500 Fixed I/O NA NA

SLC 500 Modular I/O 9-999 1999