ProSoft Technology MVI56E-MNETC User Manual

Page 50

Guide to the MVI56E-MNETC User Manual

MVI56E-MNETC ♦ ControlLogix Platform

User Manual

Modbus TCP/IP Client Enhanced Communication Module

Page 50 of 183

ProSoft Technology, Inc.

February 3, 2013

Float Flag

or N

This flag specifies how the Client driver will issue Function Code 3, 6, and 16
commands (read and write Holding Registers) to a remote server when it is
moving 32-bit floating-point data.

If the remote server expects to receive or will send one complete 32-bit floating-
point value for each count of one (1), then set this parameter to Y

. When set to

, the Client driver will send values from two consecutive 16-bit internal

memory registers (32 total bits) for each count in a write command, or receive 32
bits per count from the server for read commands. Example: Count = 10, Client
driver will send 20 16-bit registers for 10 total 32-bit floating-point values.

If, however, the remote server expects to use a count of two (2) for each 32-bit
floating-point value it sends or receives, or if you do not plan to use floating-point
data in your application, then set this parameter to N

, which is the default

setting.

You will also need to set the Float Start and Float Offset parameters to
appropriate values whenever the Float Flag parameter is set to Y

Float Start

0 to 65535

Whenever the Float Flag parameter is set to Y

, this parameter determines the

lowest Modbus Address, used in commands to a remote server, to consider as
commands to read or write floating-point data. All commands with address values
greater than or equal to this value will be considered floating-point data
commands. All commands with address values less than this value will be
considered normal 16-bit register data commands.

This parameter is used only if the Float Flag is set to Y

. For example, if a value

of 7000 is entered, all commands sent with addresses of 47001 (or 407001) and
above will be considered as floating-point data commands and 32 bits of data will
be sent or received for each count of one in the command.

You will also need to set the Float Offset parameter to an appropriate value
whenever the Float Flag parameter is set to Y

Float Offset

0 to 9999

This parameter defines the start register for floating-point data in the internal
database. This parameter is used only if the Float Flag is enabled. For example,
if the Float Offset value is set to 3000 and the Float Start parameter is set to
7000, data requests for register 7000 will use the internal Modbus register 3000.

ARP Timeout

1 to 60

This parameter specifies the number of seconds to wait for an ARP reply after a
request is issued.