MVI69E-MBS ♦ CompactLogix™ Platform
Legacy Mode
Modbus Serial Enhanced Communication Module
User Manual
ProSoft Technology, Inc.
Page 85 of 159
Parameter
Value
Description
Enable
0 to 2
This field defines whether the command is to be executed under
certain conditions.
Disabled
(0) = The command is disabled and is not executed in
the normal polling sequence.
Continuous
(1) = The command is executed each scan of the
command list if the
Poll Interval
(see below) is set to zero. If the
Poll
Interval
is set to a nonzero value, the command is executed
when the interval timer expires.
Conditional
(2) = For write commands only. The command
executes only if the internal data associated with the command
changes.
Internal Address
0 to 4999 (word-
level)
or
0 to 65535 (bit-
level)
Specifies
the module’s internal database register to be associated
with the command. Allowable range is 0 to 4999 for Modbus
Function Codes 3, 4, 6, or 16, and 0 to 65535 for Modbus
Function Codes 1, 2, 5, or 15.
If the command is a read function, the data read from the slave
device is
stored
beginning at the module’s internal database
register value entered in this field. This register value must be in
the Read Data area of the module’s memory, defined by the
Read
Register Start
and
Read Register Count
parameters in the
Module section.
If the command is a write function, the data to be written to the
slave device is
sourced
beginning from the module’s internal
database register specified. This register value must come from
the Write Data area of the module’s memory, defined by the
Write
Register Start
and
Write Register Count
parameters in the
Module section.
Note:
When using a bit level command, you must define this field
at the bit level. For example, when using function codes 1 or 2 for
a Read command, you must have a enter of 160 to place the data
in the MBS.DATA.ReadData[10] controller tag in Studio 5000.
Think of it as the 160th bit of MBS internal memory (MBS Internal
register 10 * 16 bits per register = 160). Use this formula for
function codes 5 or 15 for writing bits also.
This controller tag is a 16bit signed integer. This means you can
only enter values of -32768 to 32767 in the tag. If a value to be
entered is above the 32767 (but below 65535) threshold, it
displays as a negative value in the tag. Simply subtract 65536
from the value to get the 'acceptable' value to enter into the tag.
Example:
You need to use an Internal bit Address of 48000, but
you cannot enter '48000' into the tag because it causes an error.
48000 - 65536 = -17536 You enter -17536 in the Internal Address
parameter for this command.
Poll Interval
0 to 65535
(seconds)
Specifies the minimum interval between executions of continuous
commands (
Enable
code = 1).
Example:
If a value of 100 is entered, the command executes no
more frequently than every 100 seconds. When the command
reaches the top of the command queue and 100 seconds has not
elapsed, it is skipped until the poll interval has expired.
Register Count
1 to 125 (words)
or
1 to 800 (coils)
Specifies the number of registers or digital points to be associated
with the command. Modbus Function Codes 5 and 6 ignore this
field as they only apply to a single data point.
For Modbus Function Codes 1, 2 and 15, this parameter sets the
number of single bit digital points (inputs or coils) to be associated
with the command.
For Modbus Function Codes 3, 4 and 16, this parameter sets the
number of 16-bit registers to be associated with the command.
