Poll interval, Reg count, Swap code – ProSoft Technology MVI56E-MNETR User Manual
Page 60
MVI56E-MNETR ♦ ControlLogix Platform
Configuring the MVI56E-MNETR Module
Modbus TCP/IP Interface Module with Reduced Data Block
User Manual
Page 60 of 153
ProSoft Technology, Inc.
August 31, 2009
Poll Interval
0 to 65535
This parameter specifies the minimum interval to execute continuous commands
(Enable code of 1). The parameter is entered in tenths of a second. Therefore, if
a value of 100 is entered for a command, the command executes no more
frequently than every 10 seconds.
Reg Count
Regs: 1 to 125
Coils: 1 to 800
This parameter specifies the number of 16-bit registers or binary bits to be
transferred by the command.
Functions 5 and 6 ignore this field as they apply only to a single data point.
For functions 1, 2, and 15, this parameter sets the number of bits (inputs or
coils) to be transferred by the command.
For functions 3, 4, and 16, this parameter sets the number of registers to be
transferred by the command.
Swap Code
No Change
Word Swap
Word and Byte Swap
Byte Swap
This parameter defines if and how the order of bytes in data received or sent is to
be rearranged. This option exists to allow for the fact that different manufacturers
store and transmit multi-byte data in different combinations that do other
manufacturers. This parameter is helpful when dealing with floating-point or other
multi-byte values, as there is no one standard method of storing these data
types. This parameter can be set to rearrange the byte order of data received or
sent into order more useful or convenient for other applications. The following
table defines the valid Swap Code values and the effect they have on the byte-
order of the data.
Swap Code
Description
None
No Change is made in the byte ordering (1234 = 1234)
Swap Words
The words are swapped (1234=3412)
Swap Words & Bytes
The words are swapped then the bytes in each word are swapped
(1234=4321)
Swap Bytes
The bytes in each word are swapped (1234=2143)
These swap operations affect 4-byte (or 2-word) groups of data. Therefore, data
swapping using these Swap Codes should be done only when using an even
number of words, such as when 32-bit integer or floating-point data is involved.