Rockwell Automation 1336T Function Block Prog. Manual, Series A/B - Manual (Page 138)

5–22 Block Transfer Services
1336 FORCE — 5.9 August 1995
Header
Word 1
PLC Hex Value
8F03
4000 (hex)
Subsequent Packet Message Structure (Packets 1 – 3)
Header
Word 2
Header
Word 3
PLC Request –– Block Transfer Write
Header Word 1
Header Word 2
Header Word 3
PLC Hex Value
0F03 –– Message OK
4000 (hex)
8F03 –– Message Error
0
0
Packet Number Data Word 4
Data Word 5
Number of Events
in Packet
Data Word 6 Packet Checksum
Data Word 7 Event (Packet # * 32) + 1
• •
Data Word 38 Event (Packet # * 32) + 32
Drive Response –– Block Transfer Read
• •
• •
Message Operation for Packet 0
When Word 4 is 0, it defines packet 0, which is the command packet.
Word 5 of packet 0 defines the total number of events in the entire
application. The total number of events in the application tells the
service how many packets are required to complete a download. The
number of packets required is determined by the number of events
divided by 32, rounded up to the next highest integer.
When Word 4 is 0, Word 6 contains the execution list checksum.
The execution list checksum is the summation of all the values that
represent each event. For example, if you have an execution list with
two function blocks, 0115 and 021A, the execution list checksum
would be 032F. If the sum of the execution list is more than four
digits (hexadecimal), then you should use the right–most (least
significant) digits. For example, if the sum of the events is
10ABCD, the checksum would be ABCD.
Download and Compile
(continued)