ProSoft Technology ControlLogix inRAx MVI56E-MNETR User Manual page 86

Ladder Logic
User Manual
MNETRPASSTHRU
During pass-through operation, write messages received at the MVI56E-MNETR
server write messages through to the processor. It is the responsibility of the
ladder logic to process the message received using this feature. Two data
objects are required for this mode: a variable to hold the length of the message
and a buffer to hold the message.
This information is passed from the module to the processor using a block
identification code of 9996 if the unformatted pass-through mode (code 1) is
selected as the pass through mode in the configuration file. Word one of this
block contains the length of the message and the message starts at word 3.
Other controller tags are required to store the controlled values contained in
these messages. The Modbus protocol supports control of binary output (coils -
functions 5 and 15) and registers (functions 6 and 16).
Additionally, formatted message blocks can be sent from the module to the
processor when the pass-through option is selected using the format selection
(codes 2 or 3 in the MNET.CFG file). These blocks require less decoding than
the unformatted blocks. Refer to the user manual for a full discussion on utilizing
the pass-through option in an application.
The following table describes the structure of this object.
Name
MBControl1
MBControl2
MBMsg
MBScratch
MBOffsetBit
MBOffset
MBMsgLen
mbdouble
MBCoil
MNETRCOILARRAY
Name
Boolean
MNETRIPADDRESS
Data structure to get and set the IP address of the module.
Name
IPGetTrigger
IPReceived
IPSetTrigger
IPRequested
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Modbus TCP/IP Interface Module with Reduced Data Block
Data Type
CONTROL
CONTROL
SINT[500]
INT[3]
INT
INT
INT
DINT
MNETRCOILARRA
Y (page 86)
Data Type
BOOL[416]
Data Type
BOOL
INT[4]
BOOL
INT[4]
MVI56E-MNETR ♦ ControlLogix Platform
Description
Modbus pass thru message control
Modbus pass thru message control
Message array
Temporary used ints
Offset bit in the message
Start offset in the message
The length of the Modbus message in bytes
Modbus double int tag
Conversion from Bool to INT data types
Description
Conversion from Bool to INT data types
Description
Gets IP address
IP address received
Sets IP address
IP address set
ProSoft Technology, Inc.
June 14, 2011