Modbus Implementation - Siemens US2:9810T24V User Manual

Communications
Modbus commands
A Modbus client command to unit ID 0 is broadcast (sent to) all Modbus server devices. The only
supported broadcast command is preset multiple registers.
For serial Modbus networks with only one server device, the client can send commands using the
single connection, one-to-one address of unit ID 248, regardless of the server device's actual unit
ID.

Modbus implementation

Your meter's Modbus implementation includes exception codes, invalid register responses, fixed
and configurable register maps, and security.
Modbus exception codes
Code
01
02
03
Modbus invalid read registers responses
Invalid type
Unmapped (unused)* register
Reserved* register responses by type
Signed integer 16-bit
Unsigned integer 16-bit
Signed integer 32-bits
Unsigned integer 32-bits
Signed integer 64-bits
Float32
105
Name
Illegal function
Illegal address
Illegal value
Description
The requested command is invalid.
This code indicates one of the following:
• The requested address is invalid for that
function.
• The requested address is not within the
valid register range for this device.
• The requested address is protected by
device security.
This code indicates one of the following:
• The requested value is not allowed for that
register in the device.
• The requested register is part of a multi-
word value.
Read response
0x8000
0x8000
0xFFFF
0x80000000
0xFFFFFFFF
0x8000000000000000
0xFFC00000
(NaN = Not a number)
9810 series - User manual
7EN05-0390-08