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Register
number
R00005
R31005
R43010
Special Naming Conventions
Special Data Item
Unsigned 16-bit Integer
16-bit Signed Integers with
values between -32,768 and
32,767
32-bit Signed Integers
(Long Integers)
32-bit floating point numbers
Modulus 10000
Used in 32-bit register mode
for EPM 3710 and 3720.
ASCII data string
82 • • • • Appendix A – Register Addressing Conventions
Examples
Here are some examples of different types of register numbers:
Represents
Coil command, number 5, with Read/Write access to the user
Dynamic value, number 1005, Read Only access
Fixed value or Setpoint, number 3010, with Read /Write access
to the user
Special handling of data from devices can be done by using the following
conventions:
Long Words and Special Numbers
By default, a register item is treated as an unsigned integer. To treat the contents of
any register differently, refer to the table below:
Naming Convention
Default
Append letter I to item number.
Append L to item number.
Append F to item number.
Append E to the item name
NOTE: See 3710 and 3720 ACM Modbus Protocol Manuals for
details.
Append S to item number.
[lll] field immediately after S character represents the number of
characters to read. If no length is specified ([lll] field is not
provided), only one register of characters (2 or 4) will be read. The
High byte represents the first character, and the Low byte represents
the second character.
NOTE: No array type is allowed with S data items, nor are ASCII
strings supported for coil registers.
NOTE 2: For 16-bit mode devices (most devices) there are 2
characters per register. For 32-bit mode devices, there are 4
characters per register.
NOTE 3: The maximum value for the S string is 250.
Example
R40001
R40001I
R40001L
R40001F
R40010E
R40010S020
DDE Server User's Guide
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