ProSoft Technology MVI71-MNET - Manual (Page 65)

Reference MVI71-MNET ♦ PLC Platform
User Manual Modbus TCP/IP Interface Module
ProSoft Technology, Inc.
Page 65 of 109
June 23, 2009
Word Description
5 This word contains the TCP service port the message will be interfaced. For example, to
interface with a MBAP device, the word should contain a value of 502. To interface with a
MNET device, a value of 2000 should be utilized. Any value from 0 to 65535 is permitted.
A value of 502 will cause a MBAP formatted message to be generated. All other values
will generate an encapsulated Modbus message.
6 This word contains the Modbus node address to use with the message. This field should
have a value from 0 to 247.
7 This word contains the internal Modbus address in the module to be used with the
command. This word can contain a value from 0 to 4999.
8 This word contains the count parameter that determines the number of digital points or
registers to associate with the command.
9 The parameter specifies the swap type for the data. This function is only valid for function
codes 3 and 4.
10 This word contains the Modbus function code to be used with the command.
11 This word contains the Modbus address in the slave device to be associated with the
command.
12 to 63 Spare
The module will respond to each command block with a read block. The following
table describes the format of this block.
Word Description
0 This word contains the block identification code 2000 requested by the processor.
1 This word contains the next read request block identification code.
2 This word contains the result of the event request. If a value of one is present, the
command was issued. If a value of zero is present, no room was found in the command
queue.
3 to 63 Spare
Word two of the block can be used by the ladder logic to determine if the
command was added to the command queue of the module. The command will
only fail if the command queue for the port is full (100 commands for each
queue).
Command Control
Command control blocks place commands in the command list into the
command queue. The client has a command queue of up to 100 commands. The
module services commands in the queue before the user defined command list.
This gives high priority to commands in the queue. Commands placed in the
queue through this mechanism must be defined in the module's command list.
Under normal command list execution, the module will only execute commands
with the Enable parameter set to one or two. If the value is set to zero, the
command is skipped. Commands may be placed in the command queue with an
Enable parameter set to zero using this feature. These commands can then be
executed using the command control blocks.
One to six commands can be placed in the command queue with a single
request. The following table describes the format for this block.
Word Description
0 Command queue block identification code of 5001 to 5006.
1 This word contains the index in the command list for the first command to be entered
into the command queue.