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Data Highway Message Set
Chapter 8
830
TNS
2 Bytes
CMD
0F
USER
NODE
LINK
STS
00
FNC
00
TNS
2 Bytes
CMD
4F
USER
NODE
LINK
STS
00
Command Format:
SuccessReply Format:
TOTAL
TRANS
L ADDR
251 Bytes
DATA
239 Bytes Max.
PACKET
2 Bytes
OFFSET
Unless otherwise stated, values shown are in hexadecimal, and each block
shown represents one byte.
Read Block
Use this command to read a block of words from the destination. Use the
address (L ADDR) field to specify a starting logical word address; keep
the address constant throughout a complete transaction. In the first packet
of a transaction, the packet-offset value is 00. In subsequent packets of a
transaction, use the packet-offset field to specify the word offset (within
the block) at which the read starts for the packet. Use the total-transaction
field to specify the number of bytes to read in the total transaction. Use
the SIZE field to specify the number of bytes to read for the specific
packet.
TNS
2 Bytes
CMD
0F
USER
NODE
LINK
STS
00
FNC
01
TNS
2 Bytes
CMD
4F
USER
NODE
LINK
STS
00
Command Format:
SuccessReply Format:
TOTAL
TRANS
L ADDR
251 Bytes
SIZE
DATA
244 Bytes Max.
PACKET
2 Bytes
OFFSET
Unless otherwise stated, values shown are in hexadecimal, and each block
shown represents one byte.