Instruction Manual

Specifying Message Packet Commands
with Send_StdDrv()
Appendix B
B-10
Command Format
CMD
FNC
SIZE
FILE
ELEMENT
NUMBER
FILE
TYPE
SUB–ELMT.
NUMBERNUMBER
BYTETNSSTS
0F A2
Byte No.:
1 2 3,4 5 6 7 8 9 10
Table C.A gives a description of each field.
T able B.D
Protected T yped Logical Read with Three Address Fields
Byte Description
CMD 0F
STS Indicates the status of a message transmission
TNS A unique 16-bit transaction number . Use it to match a reply
message to its corresponding command, which contains the
same number .
FNC A2
BYTE SIZE the size of data to be read (in bytes), not including the
address fields or other overhead bytes
FILE NUMBER (or
bytes 7a-7c)
Byte 7 addresses files 0-254 only. For higher addresses,
byte 7a = FF expands FILE NUMBER to three bytes total.
Use bytes 7b and 7c for expanded file address (low address
byte first)
FILE TYPE 80H, 81H – Reserved
82H – Output
83H – Input
84H – Reserved
85H – Bit
86H – T imer
87H – Counter
88H – Control
89H – Integer
ELEMENT NUMBER
(or bytes 9a-9c)
Byte 9 addresses elements 0-254. For higher addresses,
byte 9A = FF expands ELEMENT NUMBER to three bytes
total. Bytes 9b and 9c are used for expanded element
address (low address byte first)
SUB-ELEMENT
NUMBER (or bytes
10a-10c)
Byte 10 only addresses sub-elements 0-254. For higher
addresses, byte 10a = FF expands SUB-ELEMENT
NUMBER to three bytes total. Bytes 10b and 10c are used
for expanded sub-element address (low byte first)
Protected Typed Logical Read
with Three Address Fields (File,
Element, Sub-element)