Conductivity Settings - Xylem ODO RTU User Manual

5.6

Conductivity Settings

Derived parameters from the conductivity sensor can be adapted by the user. This affects specific conductance and total dissolved
solids (TDS) values.
TDS Coefficient
In ODO/CT probes, the coefficient used to calculate TDS can be modified by the user. The value is set by writing an entire block
of values (non-divisible) using a write multiple registers command (function code 0x10). This information can be broadcast to all
devices on the network. The default value is 0.65 and is saved over power cycles. Valid values range from 0.3 to 1.0.
Address Description
0x0500
TDS Coefficient [3:0]
0x0501
Request
Function Code
Register Address
Number Registers
Byte Count
Register Values
Specific Conductance Temperature Reference
In ODO/CT probes, the standard temperature reference used to calculate specific conductance can be modified by the user. The
value is set by writing an entire block of values (non-divisible) using a write multiple registers command (function code 0x10). This
information can be broadcast to all devices on the network. The default value is 25C and is saved over power cycles. Valid values
range from 15C to 25C.
Address Description
0x0502
Specific Conductance Temperature Reference (C) [3:0]
0x0503
Request
Function Code
Register Address
Number Registers
Byte Count
Register Values
Modbus Configuration & Commands
1 byte
2 bytes
2 bytes
1 byte
4 bytes
1 byte
2 bytes
2 bytes
1 byte
4 bytes
0x10
0x0500
0x0002
0x04
TDS Coefficient [3:0]
0x10
0x0502
0x0002
0x04
Specific Conductance Temperature Reference (C) [3:0]
28
R/W Type Default
RW Float 0.65
R/W Type Default
RW Float 25