Other Modbus Addressing Schemes - ProSoft MVI56E-MCMR User Manual

MVI56E-MCMR ♦ ControlLogix Platform
Modbus Communication Module with Reduced Data Block

2.3.5 Other Modbus Addressing Schemes

While the above information will handle most devices, some device
manufacturers show their Modbus addressing differently.
The two most common schemes are six-digit addressing (400101, 301000, and
so on) and some devices show their addressing already as an offset address (the
address that actually goes out on the Modbus communication line). When
addresses are given as actual offset addresses, they are usually given as a
hexadecimal (base 16) number. This is an example.
Actual Values (Input Registers) Addresses: 0200 to 0E1F
STATUS
If your device manufacturer gives you addressing like this "Input Registers"
example above, then you will use Function Code 4 to convert the hexadecimal
value to a decimal equivalent value, and place the decimal value in the MB
A D
DDRESS IN
(Input Registers) with a MB A
"Switch Input Status" value.
What if my slave shows addresses such as 400,001 or 301,345?
For 6-digit addressing, use the same function codes and configuration as shown
above, but subtract higher values; 100001 instead of 10001; 300001 instead of
30001; and 400001 instead of 40001.
Function Codes 1, 5, or 15 MB Address in Device = Modbus Coil address in
slave device - 000001

For Modbus Coil address 000001; MB Address in Device = 0

For Modbus Coil address 001378; MB Address in Device = 1377
Function Code 2 MB Address in Device = Modbus Input Status address in slave
device - 100001

For Modbus Input Status address 100001; MB Address in Device = 0

For Modbus Input Status address 100345; MB Address in Device = 344
Function Codes 3, 6, or 16 MB Address in Device = Modbus Holding Register
address in slave device - 400001

For Modbus Holding Register address 400001; MB Address in Device = 0

For Modbus Holding Register address 400591; MB Address in Device = 590
Function Code 4 MB Address in Device = Modbus Input Register address in
device - 300001

For Modbus Input Register address 300001; MB Address in Device = 0

For Modbus Input Register address 304290; MB Address in Device = 4289
For example:
ProSoft Technology, Inc.
0200
0201
0202
0203
field. So for this example device, use Modbus Function = 4
EVICE
DDRESS IN
Configuring the MVI56E-MCMR Module
Switch Input Status
LED Status Flags
LED Attribute Flags
Output Relay Status Flags
D of 512 decimal (200h) to read the
EVICE
User Manual
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