ABB TPU2000 - Page 270

TPU2000/2000R Modbus/Modbus Plus/ Modbus TCP/IP Automation Guide
260
Figure 8 - Upload Data Communication Flow
3-Download Data:
These commands edit the TPU2000 data. The TPU2000 responds with an ACK after the successful
receipt of each data message packet. This can be seen in the figure below.
Figure 9 - Download Data Communication Flow
Message Packet Checksum:
This checksum is different than the checksum associated with every incom message packet. The
value of the checksum is contained in a two byte integer and is the summation of all message bytes (1/1 + 1/2 + 1/3 + 2/1 +
2/2 + ...) for the command. The only exception is that the checksum message bytes are not included in the summation.
Example (3 3 1 command): (values are hex equivalent of the ASCII)
1/1 = hex 05 3/1 = hex 44
1/2 = hex 31 3/2 = hex 00
1/3 = hex 04 3/3 = hex 00
2/1 = hex 00 4/1 = hex 00
2/2 = hex 01 4/2 = hex 00 <-- checksum high byte
2/3 = hex 44 4/3 = hex C3 <-- checksum low byte
Command Set Summary
Inst
Cmd Subcmd Definition
3 0 n Status Commands
3 1 n
3 2 n
3 3 n Transmit Settings Commands
3 4 n Transmit Settings Commands
3 5 n Transmit Meter/Record Commands
3 6 n Load Profile/Record Commands
3 7 n Transmit Meter Commands
3 8 n
3 9 n Relay Commands
Master
Command
Data
Data
Data
.
.
.
DPU2000
Master
Command
Data
Data
Data
.
.
.
ACK
ACK
ACK
DPU2000