Yokogawa EJX930A - Manual (Page 35)

<5. Modbus Communication>
5-4
IM 01C25R05-01EN
5.6 Data format
(1) USIGN INTEGER FORMAT
This format is used for integer data.
There are a number of 8 bit values that are stored in
16 bit registers. The 8 bit value is stored in the Least
Significant Byte of the 16 bit register. E.g. 0x24 is
stored as 0x0024.
(2) IEEE 754 FLOATING POINT FORMAT
Floating point values are stored as single precision
IEEE 754 floating point numbers. Since
IEEE 754 floating point numbers are 32 bits long.
Data is stored in the order of MSB (Most significant
byte) first.
E.g. 100.25 is stored as 0x42C88000.
(3) DATE FORMAT
This format is used for date information.
Date: DD, Month: MM, Year: YY is stored as
0x00DDMMYY.
Year: YY means the offset year from Year 1900.
E.g. 30th September 2013 is stored as
0x001E0971.
5.7 Address Map
Address map consists of Basic Information and
Detail Information.
Category Address Type
Address
(Decimal)
Basic Information Coils 0003 to 0033
Discrete Inputs 0050 to 0075
Input Registers /
Holding Registers
0001 to 0454
Detail Information Coils 1001 to 1005
Discrete Inputs 1001 to 1088
Input Registers 1001 to 1316
Holding Registers 1001 to 2117
NOTE
• Some data is mapped in both area of Basic
Information and Detail Information.
• Enumeration table list is described
commonly both for Basic Information and
Detail Information.
• The data of Input Register and Holding
Register in Basic Information area can be
read by both function codes.
• In order to access 0001 parameter, set 0000
in communication frame.
• The return value is uncertain when
communicated to address which is not
written in the map.