Reporting Reserved Addresses - ABB Remote I/O RIO600 Installation And Commissioning Manual

Section 7
Modbus TCP communication
7.1.29
Table 124: Correlation between the function code and address range
Module Data type
name
DOM4 Boolean
DIM8H/ Boolean
DIM8L
RTD4 Signed 16
bit channel
status
informatio
n
Channel
range
informatio
n
(unsigned
16)
AOM4 Signed 16
bit channel
status
informatio
n
SIM8F/ Readable
SIM4F data
Boolean
Writeable
data
Boolean
Signed 32
bit Analog
data and
Signed 16
bit enum
SCM Boolean
SSR SSR1 and
SSR 2
unsigned
16 bit
informatio
n
Table continues on next page
182

Reporting reserved addresses

Considering RIO600 expansion, the Modbus point list depicts several addresses
reserved for future use. In the current implementation, if a 3X/4X read poll is made for
a Modbus address which is reserved for future use, the value "0" is reported to the
Modbus master. The Modbus master must be able to poll for a maximum number of
data points in one single poll and it should not return an exception in case a reserved
address region falls between two unreserved or currently assigned Modbus address
regions. However, during a write poll (4X), if a Modbus master is trying to write the
value to a Modbus address which is reserved for future use, an exception is returned
to the Modbus master.
0X 1X
Readable Writeable Readable
(FC 01) (FC 05) (FC 02)
Yes Yes No
No No Yes
No No No
No No No
No No No
No No Yes
Yes Yes
No No No
Yes Yes Yes
No No No
3X
Writeable Readable Writeable
(FC 04)
No Yes No
No Yes No
No Yes No
No Yes No
No Yes No
No Yes No
No Yes No
No Yes No
No Yes No
No Yes No
Installation and Commissioning Manual
1MRS757488 H
4X
Readable Writeable
(FC 03) (FC 06)
Yes Yes
Yes No
Yes No
Yes No
Yes Yes
Yes No
Yes Yes
Yes No
Yes Yes
Yes No
RIO600