ProSoft Technology MVI94-MCM-MHI - Manual (Page 26)

Configuration MVI94-MCM ♦ Flex I/O Platform
User Manual Serial Communications Modbus Communication Module
Page 26 of 109 ProSoft Technology, Inc.
March 29, 2011
Read Floating-Point Data
Here is the addressing of a Slave device, with a parameter "Energy
Consumption" that is shown as two registers 40257 and 40258.
Value Description Type
40257 -------- KWH Energy Consumption Float, lower 16 bits
40258 KWH Energy Consumption Float, upper 16 bits
To issue a Read command to this parameter, use the following configuration.
Parameter Value Description
Enable 1 Sends the command every time through the command list.
IntAddress 1000 Places data at address 1000 of the module memory. Based on the
configuration in ModDef this will put the data at the tag
MCM.DATA.R
EAD D ATA [0].
PollInt 0 No delay for this command.
Count 2 Reads 2 consecutive registers from the Slave device. These 2
Modbus registers will make up the "Energy Consumption" floating-
point value.
Swap 0
Swap Code Description
0 None - No Change is made in the byte ordering
(1234 = 1234)
1 Words - The words are swapped (1234=3412)
2 Words & Bytes - The words are swapped then
the bytes in each word are swapped
(1234=4321)
3 Bytes - The bytes in each word are swapped
(1234=2143)
Node 1 Sends the command to Node #1.
Func 3 Issues a Modbus Function Code 3 to "Read Holding registers."
DevAddress 256 Along with the Function Code 3, DevAddress 256 will read
Modbus address 40257 of the Slave device.