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6053/6055 Modbus Plus Communications Interface
Configuring the PLC/SCADA Supervisor
This chapter contains an example for configuring a PLC.
1.
Start a new program and select
the PLC processor and chassis
type that is used in your
project. Our example uses a
M1 980-20 Momentum PLC.
Remain Offline until you are
ready to download the
program.
2.
Place a MSTR block in the
ladder logic. MSTR blocks
move data from the PLC data
table to the drive or from the
drive to the PLC data table.
Two MSTR blocks will be
necessary for a Read and
Write operation. The Read
MSTR block is required for
proper operation and transfer
of data.
3.
Right click over the MSTR
block, this will access the
Register Editor. Use the
Register Editor to configure
the block. The MSTR block
has two types of operations
Read or Write. The first
register defines the type of
operation. In our case address
40100 is used for write command and address 40200 is used for read command. A value of
1 in the data column defines a write operation. A value of 2 in the data column defines a
read operation.
4.
The second register contains the error status. Refer to Appendix A for a list of the error
codes. The PLC software also has help files that contain a list of error codes.
Figure 6 PLC Ladder Logic Showing MSTR Blocks
Figure 7 Read Registers
