ProSoft Technology MVI56E-MCMR - Manual (Page 61)

MVI56E-MCMR ♦ ControlLogix Platform Configuring the MVI56E-MCMR Module
Modbus Communication Module with Reduced Data Block User Manual
ProSoft Technology, Inc. Page 61 of 225
May 13, 2014
Parameter Description
Internal Address 0 to 4999 for Register-level commands
0 to 65535 for Bit-level commands
Determines the starting address in the module’s 5000-register
database that will be affected by the command. For a Read
command, this will determine where the data will begin to be placed
in the module database after it has been read from a slave. For read
commands, you should configure this value so that the data will be
placed in the range of module memory designated for ReadData, as
defined in the Backplane Configuration section of this configuration
file.
For write commands, the I NTERNAL A DDRESS determines where to
begin obtaining the data to write to the slave device. This must be a
location that is in the WriteData area of module memory, as defined
in the Backplane Configuration section of this configuration file.
Note: When using a bit-level command, you must define this field at
the bit level. For example, when using a Function Code 1, 2 for a
Read command, you must have a value of 16000 to place the data in
MCM.ReadData[0] (ReadStartRegister = 1000 * 16 bits per register =
16000).
Poll Interval 0 to 65535
The Poll Interval is the number of seconds that the Master will wait
between successive executions of this command. Set to zero (0) for
the fastest possible polling.
This parameter can be used to prioritize and optimize network traffic
by assigning low values to high-priority poll requests and assigning
higher values to less important data poll commands.
Reg Count 1 to 125 words for Function Codes 3, 4, and 16 (Register-level)
1 to 2000 for Function Codes 1, 2, and 15 (Bit-level)
Sets how many continuous words (Function Codes 3, 4, and 16) or
bits (Function Codes 1, 2, and 15) to request from the slave device.
Note: These values are the maximum allowed in the Modbus
protocol. Some devices may support fewer words or bits per
command than these maximum values.
Swap Code N O C HANGE , S WAP W ORDS , S WAP W ORDS & B YTES , S WAP B YTES
Typically used when reading floating-point data. Swaps the data read
from the slave device before it is placed into the module memory. For
example, you receive 4 bytes of data from the slave (ABCD).
N
O C HANGE = No swapping (ABCD)
S WAP W ORDS = Word pairs switched (CDAB)
S WAP W ORDS AND B YTES = Bytes and words switched (DCBA)
S WAP B YTES = Bytes swapped (BADC)
Node Address 1 to 247
Modbus Slave Device Address of the device on the network to read
data from, or write data to. Valid addresses are 1 to 247. Address 0 is
reserved for broadcast write commands (will broadcast a Write
command to all devices on the network).