RLE 10K V.2.5.a User Manual
Page 36
36
SeaHawk 10K User Guide
800.518.1519
4
Modbus Communication
5
Add up all the lengths of sensing cable and any other equipment in the system that
simulates a length of cable. Record this value. Keep in mind:
♦
Each weighted cable connector (WCCS-50) simulates 50 feet (15.24m) of cable.
♦
Each SD-Z simulates 50 feet (15.24m) of cable.
♦
Each X-Connector (XCON) simulates 150 feet (45.72m) of cable.
6
Divide the Leg 2 resistance by the total length of cable. This value is the resistance of the
cable installed on your system in ohms per foot. This ohms per foot value is for your
reference only (the ohms per foot value will have a decimal point in it, and you cannot write
a number with a decimal point to register 40008). Record this value.
Multiply the value in ohms per foot by 1000. This will give you the value in milliohms per
foot. This milliohms per foot value is your end result, and the number you will write to
Modbus register 40008. Record this value.
7
Access your Modbus-enabled system. Write the milliohms per foot resistance value to the
SeaHawk 10K’s Modbus register 40008.
Example:
♦
The Leg 2 resistance reading on the system is 2091 ohms.
♦
The system has 400 feet of sensing cable,
1 X-Connector - which simulates 150 feet of sensing cable,
4 SD-Zs which simulate 50 feet of cable each, for a total of 200 feet of sensing cable
System-wide, there are 750 feet of actual and simulated cable.
♦
Divide 2091 ohms by 750 feet of cable. You get a resistance of 2.788 ohms per foot.
♦
Multiply 2.789 ohms per foot by 1000 to get 2788 milliohms per foot.
♦
Access Modbus register 40008 and record the new milliohms per foot value, 2788.
Leg2 Resistance (Modbus register 30007)
(Modbus register 40008)
Resistance per foot
in milliohms/foot
Total Feet of Cable Installed on the System
X
1000
2091
750
2788