Precision Digital PD865 - Manual (Page 79)

PD865 Modbus Snooper Serial Input Meter Instruction Manual
79
Register Table Notes
Note 1. Although there are no specific 3x registers listed, all 4x Registers are
mirrored into 3x register space, and are therefore capable of being
read by Modbus function 04 (Read Input Registers). Register
addresses in Modbus messages are referenced to zero (0), while
Register numbers are referenced to one (1). For example, Register
number 40100 is sent in the Modbus message as 0x0063 (100-1 = 99
≡ 63 hex). If two addresses are shown separated by a “ – ”, they form
a register pair to make the parameter into a 4-byte (32 bit) value.
Note 2. Limits or Range: Writing a value that is outside the parameters
range will force it to be limited to the closest value within the range.
For example; if the range is -1.99 to +1.99 and the value sent is 3.21,
the value used is 1.99, or if -4.00 is sent, the value used will be -1.99.
Exceptions are noted in the comments.
Note 3. Data Types:
Data format is highest byte first.
Word = 16 bit
Integer = -32768 to 32767
Long = -2,147,483,648 to 2,147,483,647
Float = IEEE floating point format, 4 bytes
”Display decimal point setting in 40013.” These values represent the
number without regard to the decimal point. The decimal point setting
can be found in Holding Register 40013. For example, if the number
12.34 is displayed, a read of 40001-40002 will return 1234
(0x000004D2). Register 40013 will contain 2 (0x0002) to indicate a
decimal point setting of two places to the right of the decimal point.
Examples using integer and long (register values are
shown in hexadecimal):
Displayed
Process Value
Register
40001 - 40002
Register
40013
1.234 0000 04D2 0003
12.34 0000 04D2 0002
123.4 0000 04D2 0001
-123.4 FFFF FB2E 0001