Application note
Integrated Modbus support
AN00198
ABB Motion control products
5
new.abb.com/motion
Depending on the product, there are two different data areas available that are used for data exchange:
•
NetData array
•
Comms array
The following table shows the use of the different data areas:
Drive/Controller
Modbus Type
Data area
MicroFlex e190
Modbus TCP Client/Server
NetData
MicroFlex e190 + OPT-SIO-1
Modbus RTU Server
Comms
MotiFlex e180
Modbus TCP Client/Server
NetData
NextMove ESB-2
Modbus RTU
Comms
e100 products
Modbus RTU/TCP
Comms / NetData
(see MODBUSPARAMETER below)
For e100 products we can choose where the data goes set by the Mint keyword MODBUSPARAMETER:
NetData array:
MODBUSPARAMETER(_busSERIAL1, _mpREGISTER_MAPPING) = _rmNET_DATA
Comms array:
MODBUSPARAMETER(_busSERIAL1, _mpREGISTER_MAPPING) = rmCOMMS_ARRAY
This data area has a fixed mapping with respect to how it appears to a Client device as Modbus registers as shown by the table
below (equivalent AC500 addresses are also shown for reference):
Server Modbus
register
AC500 address
Mint Comms array
(Comms=Real, Commsinteger = DWord)
Mint Netdata array
(Netfloat = Real, Netinteger = DWord)
0
%MW0.0
%MD0.0
Invalid
Invalid
Element 0 LSW
Element 0
1
%MW0.1
Invalid
Element 0 MSW
2
%MW0.2
%MD0.1
Element 1 LSW
Element 1
Element 1 LSW
Element 1
3
%MW0.3
Element 1 MSW
Element 1 MSW
4
%MW0.4
%MD0.2
Element 2 LSW
Element 2
Element 2 LSW
Element 2
5
%MW0.5
Element 2 MSW
Element 2 MSW
…
---
---
---
---
---
---
198
%MW0.198
%MD0.99
Element 99 LSW
Element 99
Element 99 LSW
Element 99
199
%MW0.199
Element 99 MSW
Element 99 MSW
200
%MW0.200
%MD0.100
Invalid
Invalid
Element 100 LSW
Element 100
201
%MW0.201
Invalid
Element 100 MSW
202
%MW0.202
%MD0.101
Invalid
Invalid
Element 101 LSW
Element 101
203
%MW0.203
Invalid
Element 101 MSW
…
---
---
---
---
---
---
1996
%MW0.1996
%MD0.998
Invalid
Invalid
Element 998 LSW
Element 998
1997
%MW0.1997
Invalid
Element 998 MSW
1998
%MW0.1998
%MD0.999
Invalid
Invalid
Element 999 LSW
Element 999
1999
%MW0.1999
Invalid
Element 999 MSW
LSW
– Least Significant Word : MSW – Most Significant Word
The Mint Comms array provides 99 elements (1-99). If the Client attempts to access Comms element 0 or Comms elements
greater than 99 the Mint controller will return the ‘Invalid Data Address’ Modbus exception packet.
The Mint Netdata array (not supported on NextMove ESB-2) provides 1000 elements (0-999). If the Client attempts to access
Netdata elements greater than 999 the e190/e180
will return the ‘Invalid Data Address’ Modbus exception packet.
Registers are addressed starting at zero. However Mint Comms locations are addressed from 1
– 99 (see also Application Note
AN00110) so care should be taken not to try to read or write register 0 on the Mint controller if using Comms instead of
NVLONG.