Allen-Bradley DF1 Full Duplex communication protocol
Supported device types and versions
Communication line configuration
Communication station configuration
I/O tag configuration
Literature
Changes and modifications
Document revisions
Required setting of the 1770-KF3 device
Supported device types and versions
The protocol Allen-Bradley DF1 Full Duplex supports communication with Allen-Bradley devices of the SLC-500 series. Communication supports (is verified) for the following devices:
Table 1
| Device type | Meaning | Protocol version |
|---|---|---|
| Allen-Bradley SLC 5/04 | Communication with RS232 via the SLC 5/04 CPU port | - |
| Allen-Bradley 1770-KF3 | DH-485 bus concentrator, supports communication with all the devices of the SLC-500 series (description of setting is mentioned at the end of chapter). | - |
Communication line configuration
- Communication line category: Serial, SerialOverUDP Device Redundant.
- Serial line parameters:
- baud rate (for 1770-KF3 there can be used 300, 600, 1200, 2400, 4800, 9600 or 19200 Baud - parameter 3 of KF3 settings - RS-232C Baud Rate),
- Parity (for 1770-KF3, there can be used None or Even parity - parameter 4 of KF3 setting - RS-232C Parity),
- Handshaking (for 1770-KF3, according to the connection of the RS-232 connecting cable set the parameter 7 of KF3 setting - Flow Control).
Line protocol parameters
Configuration dialog box - tab
Parameters, select the protocol Allen-Bradley DF1 Full Duplex.
They influence some optional parameters of protocol.
Table 2
| Parameter | Meaning | Unit | Default value |
|---|---|---|---|
| BCC/CRC Checksum | Type of security by check sum. | CRC BCC |
CRC |
| Full Debug | Activates detailed listings about sending and receiving values. | 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 protocol.
Table 3
| Parameter | Meaning | Unit | Default value |
|---|---|---|---|
| Interface Node | DH-485 Node Address of the communication interface(KF3), the address in common use is 0. (Warning, when you use the 1770-KF3 device, its setting is valid for all stations of the line). | - | 0 |
| Wait First Timeout | First timeout for reading a response after sending a message. | ms | 100 |
| Wait Timeout | Timeout between response readings till its finalization. | ms | 100 |
| Max Wait Retry | Repetition number of response readings till its finalization. | - | 40 |
| Max Read Retry | Repetition number of response readings, if received response is not the response to expected transaction. All received messages are to be confirmed. | - | 10 |
| Retry Count | Retry count of the request in case of a communication failure. | - | 3 |
| Block Read | Enables block data read. It is executed by non-documented functions - proceed carefully. | YES/NO | NO |
| Max. Block Length | Maximum block length for block read (in bytes). Value must be a even number within the range of 2 up to 254. | - | 40 |
I/O tag configuration
Possible I/O tag types: Ai, Ao, Ci, Co, Di, Dout.
I/O tag address is an address in text form in the SLC-500 form. Address format is:
[$] X [file] : element [.field] [/bit]
in which
| $ | optional character, |
| X | file type identifier (required - see the table nr. 3), |
| file | file number (optional, if not defined, there will be used the default file number according to the table nr. 3), |
| element | number of element in the file (required), |
| .field | sub-element number (optional, used for Output, Input files only), |
| /bit | bit number (optional, must be within the range of 0..15). |
Table 4
| X | File Type | Default file number |
|---|---|---|
| O | Output | 0 |
| I | Input | 1 |
| S | Status | 2 |
| B | Binary | 3 |
| N | Integer | 7 |
| F | Float | 8 |
Output type file
[$]O[n]:e[.s][/b]
"n" file number - if there is used other than the default number of 0,
"e" element number in the file,
"s" sub-element number (0..255),
"b" bit number (0..15).
For example:
O:2 $O0:2/0 O:1.0/1
Note: You cannot write into Output files, only read data.
Input type file
[$]I[n]:e[.s][/b]
"n" file number - if there is used other than the default number of
1,
"e" element number in the file,
"s" sub-element number (0..255),
"b" bit number (0..15).
For example:
I:1 $I1:2/0 I:2.0/15
Note: You cannot write into Input files, only read data.
Status type file
[$]S[n]:e[/b]
"n" file number - if there is used other than the default number of
2,
"e" element number in the file,
"b" bit number (0..15).
For example:
S:0 $S2:40 S:2/15
Note: You cannot write bit-by-bit into Status type files (output I/O tags with the parameter [/b]).
Binary type file
[$]B[n]:e[/b]
"n" file number - if there is used other than the default number of
3,
"e" element number in the file,
"b" bit number (0..15).
For example:
B:2 $B3:0 B3:2/1
Integer type file
[$]N[n]:e[/b]
"n" file number - if there is used other than the default number of
7,
"e" element number in the file,
"b" bit number (0..15).
For example:
N7:2 $N:0 N27:0/1
Float type file
[$]F[n]:e
"n" file number - if there is used other than the default number of
7,
"e" element number in the file.
For example:
F:0 $F8:0 F29:1
Required setting of the 1770-KF3 device
Further required parameters for 1770-KF3 device:
- Set the Parameter 0 DH-485 Node Address to 0. You can use other address, see „Communication station protocol parameters" - the parameter „IN",
- Set the parameter 5 DF1 Device Category to DF1 full-duplex,
- The parameter 6 Error Detection - there can be used both BCC and CRC16, see „Communication station protocol parameters" - the parameter „BCC",
- For the others parameters, there are suitable default settings described in the document „1770-6.5.18, DH-485 Communication Interface User Manual (Cat. No. 1770-KF3)", Allen-Bradley April 1993.
Literature
- "1770-6.5.18, DH-485 Communication Interface User Manual (Cat. No. 1770-KF3)", Allen-Bradley - April 1993.
- "1770-6.5.16, DF1 Protocol and Command Set, Reference Manual", Allen-Bradley - October 1996.
Changes and modifications
-
Document revisions
- Ver. 1.0 - August 22nd, 2000 - document creation.
- Ver. 1.1 - April 27th, 2009 - update of document.
Related pages: