Allen-Bradley DF1

Allen-Bradley DF1

Allen-Bradley DF1 Full Duplex communication protocol

Supported device types and versions


The Allen-Bradley DF1 Full Duplex protocol supports communication with Allen-Bradley devices of the SLC-500 series. Communication supports (is verified for) for the following devices:

Table 1

Device type

Meaning

Protocol version

Allen-Bradley SLC 5/04

Communication with the SLC 5/04 CPU via RS232 port

-

Allen-Bradley 1770-KF3

DH-485 bus concentrator supports communication with all the devices of the SLC-500 series (description of the setting is mentioned at the end of the chapter).

-

Communication line configuration


  • Communication line category: Serial, SerialOverUDP Device Redundant.

  • Serial line parameters:

    • Baud rate (for 1770-KF3, 300, 600, 1200, 2400, 4800, 9600 or 19200 Baud can be used - parameter 3 of KF3 settings - RS-232C Baud Rate),

    • Parity (for 1770-KF3, None or Even parity can be used - parameter 4 of KF3 setting - RS-232C Parity),

    • Handshaking (for 1770-KF3, set the parameter 7 of KF3 setting - Flow Control, according to the setting of the RS-232 cable).

Line protocol parameters

Configuration dialog box - tab Parameters, select the Allen-Bradley DF1 Full Duplex protocol.
They influence some optional parameters of the protocol.

Table 2

Parameter

Meaning

Unit

Default value

BCC/CRC Checksum

Type of checksum for securing of the payload. 

CRC
BCC

CRC

Full Debug

Activates detailed listings about sending and receiving values and further debug information.

YES/NO

NO

Communication station configuration


Communication protocol: Allen-Bradley DF1
Station address: DH-485 Node Address of device in the range of 1 up to 31.

Station protocol parameters

Communication station - configuration dialog box - the Protocol parameter input field.
They influence some optional parameters of the protocol.

Table 3

Parameter

Meaning

Unit

Default value

Interface Node

DH-485 Node Address of the communication interface (KF3), the address 0 is commonly used. (Warning, when you use the 1770-KF3 device, its setting is valid for all stations of the line).

-

0

Wait First Timeout

First delay before reading the response after sending a request.

ms

100

Wait Timeout

Delay between response readings until its finalization.

ms

100

Max Wait Retry

The number of response readings till its finalization.

-

40

Max Read Retry

The number of response readings, if the received response is not the response to the expected transaction. All received messages are to confirmed.

-

10

Retry Count

A retry count of the request in case of a communication failure.

-

3

Block Read

Enables block data reading. It is executed by non-documented functions - careful proceeding is asdvised.

YES/NO

NO

Max. Block Length

Maximum block length for block reading (in bytes). The value must be an even number within the range of 2 up to 254.

-

40

I/O tag configuration