Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 131)

Message Packet Formats
Chapter 5
5-52
Table 5.F
Data Types/ID Values
Value Mnemonic Name
0
1
2
3
4
5
6
7
8
9
15
16
END
B
BS
CS
I
T
C
R
F
A
ADR
D Last Element Indicator/No Type Specification
Bit
Bit String
Byte (or Character) String
Integer
Allen-Bradley Timer
Allen-Bradley Counter
Allen-Bradley General Control Structure
IEEE Floating Point
Array of Similar Elements
Address
Binary Coded Decimal
You use the type/data parameter to determine:
the ID value for the type of data you are sending or receiving (ID
values in the table above) or
the number of bytes in the data type you are sending or receiving.
The first byte of the type/data parameter has this format:
ID
Format
Field
ID Value Field
Size
Format
Field
Size Value Field
Bit 7 6 5 4 3 2 1 0
Data Type ID
If Bit 7 is a zero (0), the data type ID value is 7 or less (see Table 5.F).
The actual ID value for the data type is then contained in the ID Value
Field (Bits 4, 5, 6).
If Bit 7 is a one (1), the data type ID value is greater than 7 (see
Table 5.F). The ID Value Field (Bits 4, 5, 6) contain the number of bytes
(following the parameter byte) which contain the data type ID value.