ProSoft Technology MVI46-MBP - Manual (Page 52)

MVI46-MBP ♦ SLC Platform Reference
Modbus Plus Communication Module
Page 52 of 101 ProSoft Technology, Inc.
February 19, 2008
+---------+
enable -¦ ¦- active
¦ 40050 ¦
+---------¦
abort -¦ ¦- error
¦ 40060 ¦
+---------¦
¦ MSTR ¦-
success
¦ 00020 ¦
+---------+
Contents of registers in the control block
40050 = 2 Read instruction
40051 = 0 Error code
40052 = 20 Length of the read
40053 = 50 slave register to read (module address 50)
40054 = 6 MVI46-MBP Node address to retrieve data from
40055 = 1 Slave Input Path for routing
40056 = 0 Routing Address 3
40057 = 0 Routing Address 4
40058 = 0 Routing Address 5
40060 = Destination address in the Modicon PLC for the
data from the MVI46-MBP module
The MSTR 2 instruction shown in the previous example reads 20 words from the
MVI46-MBP module beginning at address 50 and places the data in the Modicon
PLC beginning at address 40060.
Note that the Slave Input Path value must be entered in order for the command
to execute successfully. Valid values are from 1 to 8. Any other values will cause
the command to fail.
In order for a Modicon PLC to write data to the module, a MSTR Type 1
instruction must be entered in the Modicon's ladder program. This instruction
initiates a Modbus Plus network transaction between the PLC and the module. In
the configuration of the command, the programmer can specifically choose the
destination address and the amount of data to be written to the module from the
Modicon's memory.
The following illustration shows an example configuration for a MSTR Type 1
command.
+---------+
enable -¦ ¦- active
¦ 40001 ¦
+---------¦
abort -¦ ¦- error
¦ 40010 ¦
+---------¦
¦ MSTR ¦-
success
¦ 00002 ¦
+---------+
Contents of registers in the control block
40001 = 1 Write instruction
40002 = 0 Error code
40003 = 30 Length of the write
40004 = 100 register to Write to in module
40005 = 6 MVI46-MBP Node address to write to
40006 = 1 Slave Input Path for routing
40007 = 0 Routing Address 3
40008 = 0 Routing Address 4
40009 = 0 Routing Address 5
40010 = Source of the data in the Modicon PLC to send to
the MVI46-MBP module
This instruction will write 30 words (from 40010 to 40039) in the PLC to the
MVI46-MBP module's database beginning at Data Register address 100.
Note that the Slave Input Path value must be entered in order for the command
to execute successfully. Valid values are from 1 to 8. Any other values will cause
the command to fail.