Modbus MFU Option Card Installation Manual
52 of 76
Publication PUB091-003-00_0119
7.6.7
Data Accessed with Function Code 07 – Read Exception Status
Code 07 reads a predefined data set with minimal overheads and is used for fast data transfer. A
single byte is returned.
Location
(Bit)
R/W
Data
Range
0
RO
ESD coil status
0-1
1
RO
Open coil status
0-1
2
RO
Close coil status
0-1
3
RO
Stop coil status
0-1
4
RO
Closed position limit
0-1
5
RO
Open position limit
0-1
6
RO
Monitor relay
0-1
7
RO
Reserved
0-1
7.6.8
Data Accessed with Function Code 08 – Loopback Diagnostic Test
The Loopback Test is used to test communications only. In a correctly working unit the return
message is the same as the query sent. Two codes are supported.
Code
Data
00
Return query data
02
Return diagnostic register
The Diagnostic Register contains the following data.
Location
(Reg/Bit)
R/W
Data
Range
-
0
RO
Memory Status Fault
0-1
-
1
RO
Auxiliary control input active
0-1
-
2
RO
Position controller enabled
0-1
-
3
RO
Highway ESD active
0-1
7.6.9
Data Accessed with Function Code 17 – Report Slave ID
The Slave ID data response includes 20 registers, (40 bytes) of ASCII data to give the device name,
software version and service tag number.
Byte
Data
1 – 23
‘Null Null Rotork MODBUS MODULE.’
24 – 28
Software version: ‘Mxxx ‘ (where xxx is the revision number)
29 – 40
Tag Number (12 bytes)