Technical Bulletin

Modbus RTU On-Board Communications
PowerXL DG1 Series VFD MN040010EN—May 2014 www.eaton.com 13
Modbus Registers
The variables and fault codes as well as the parameters can
be read and written from Modbus. The parameter addresses
are determined in the application. Every parameter and actual
value have been given an ID number in the application. The
ID numbering of the parameter as well as the parameter
ranges and steps can be found in the application manual in
question. The parameter value shall be given without
decimals.
All values can be read with function codes 3 and 4 (all
registers are 3X and 4X reference). Modbus registers are
mapped to drive IDs as follows.
Table 20. Index Table
Process Data
The process data fields are used to control the drive (e.g.,
Run, Stop, Reference, Fault Reset) and to quickly read actual
values (e.g., Output frequency, Output current, Fault code).
The fields are structured as follows.
Table 21. Process Data Slave R Master (max. 22 bytes)
Table 22. Process Data Master R Slave (max. 22 bytes)
The use of process data depends on the application. In a
typical situation, the device is started and stopped with the
Control Word (CW) written by the Master and the Rotating
speed is set with Reference (REF). With PD1–PD8 the device
can be given other reference values (e.g., Torque reference).
With the Status Word (SW) read by the Master, the status of
the device can be seen. Actual Value (ACT) and PD1–PD8
show the other actual values.
ID Modbus Register Group R/W
1–98 40001–40098
(30001–30098)
Actual Values 1/1
99 40099 (30099) Fault Code 1/1
101–1999 40101–41999
(30101–31999)
Parameters 1/1
2001–2099 42001–42099
(32001–32099)
Process Data In 20/20
2101–2199 42101–42199
(32101–32199)
Process Data Out 20/20
ID Modbus Register Group Range/Type
2101 32101, 42101 FB Status Word Binary coded
2102 32102, 42102 FB General Status Word Binary coded
2103 32103, 42103 FB Actual Speed 0–100.00%
2104 32104, 42104 FB Process Data Out 1
2105 32105, 42105 FB Process Data Out 2
2106 32106, 42106 FB Process Data Out 3
2107 32107, 42107 FB Process Data Out 4
2108 32108, 42108 FB Process Data Out 5
2109 32109, 42109 FB Process Data Out 6
2110 32110, 42110 FB Process Data Out 7
2111 32111, 42111 FB Process Data Out 8
ID Modbus Register Group Range/Type
2001 32001, 42001 FB Control Word Binary coded
2002 32002, 42002 FB General Control Word Binary coded
2003 32003, 42003 FB Speed Reference 0–100.00% Hz
2004 32004, 42004 FB Process Data In 1 Integer 16
2005 32005, 42005 FB Process Data In 2 Integer 16
2006 32006, 42006 FB Process Data In 3 Integer 16
2007 32007, 42007 FB Process Data In 4 Integer 16
2008 32008, 42008 FB Process Data In 5 Integer 16
2009 32009, 42009 FB Process Data In 6 Integer 16
2010 32010, 42010 FB Process Data In 7 Integer 16
2011 32011, 42011 FB Process Data In 8 Integer 16