MAGS1 User Guide
14
V1.5 22-1-2016
4.10. Modbus holding registers
In the following the holding registers for the MAGS1 Modbus RTU module are described.
Modbus
Start Register
Section
2
Password
100
Real-time measurement
1000
Info
1500
Display
2000
User settings
4000
Factory settings
Holding registers memory map
When writing to the Holding registers, data validity is not checked. Writing incorrect values can result in
unexpected behavior of the device. In any further explanations, the following data types are used:
•
Longint
– Number consisting of 32 bits, formed by 2
Modbus registers. It is necessary to write both Low and
High Word of this item, the register number always has
to be an even number. Not meeting these requirements
will cause an Exception 2 error (Illegal data address). In
case information about the number of decimals is
available, then the final number is given by the following
formula: Y = X * 10^(-DEC), where Y is the final
number, X the read number, and DEC the number of
decimals.
•
Bool
– this item can be read, but its value has no
meaning. Writing value 1 to this item will cause an
unspecified operation to be performed (resetting the
flow totalizers, etc.) It is necessary to write both Low
and High Word of this item, the register number always
has to be an even number. Not meeting these
requirements will cause an Exception 2 error (Illegal
data address).
4.11. Password
To enter the "User settings and Factory settings" sections, it is necessary to enter a password.
Modbus
register
Modbus
address
No. of
bytes
Data type
No. of
decimal
Min
Value
Max Value
Description
Read/
Write
2
1
4
Longint
0
0
9 999
Password (User) R*/W
4
3
4
Longint
0
0
9 999
Password
(Service)
R*/W
6
5
4
Longint
0
0
9 999
Password
(Factory)
R*/W
*) For safety purposes, it is not possible to read this item directly. In case a 0 is read from this register, it
means that no valid password was entered, and the given section is not accessible. In case a 1 is read, a
valid password was entered and hence the given section can be accessed freely. To close the section, you
write any possible invalid password to the password entry.
Data type memory map
Modbus
register
Data Type
Low/High
Word
2
Longint
L
3
H
4
Bool
L
5
H
6
Word
-
