KTA-282 Modbus TCP Weather Station Gateway
Figure 5: “Bad Request” XML file
Open Collector Outputs (PCB Rev 5 and later)
The KTA-282 is equipped with two open collector outputs able to sink up to 300mA. These can be user configured
to switch on/off at a given threshold of any weather data point. They are therefore useful as alarms, or for basic
control operations.
Set up is via six (6) Modbus registers:
Holding
Register
Open
Collector
Name
Function
117
1
Register
Sets the Holding Register containing the weather variable to be
monitored
118
1
Set Point
Sets the threshold at which the open collector will turn On or Off
119
1
Direction
Sets the direction of the switching behaviour. 0 = output active below
setpoint. 1 = output active above set point
120
2
Register
Sets the Holding Register containing the weather variable to be
monitored
121
2
Set Point
Sets the threshold at which the open collector will turn On or Off
122
2
Direction
Sets the direction of the switching behaviour. 0 = output active below
setpoint. 1 = output active above set point
Example:
Wind speed is held in register 23. I am on a farm where the roof of my tin shed will blow off above 70 km/h gusts. At
50km/h I want a buzzer to sound as a warning.
I write 23 into register 117, 50 into register 118, and 1 into register 119. The output will turn
on
the buzzer if the
windspeed goes above 50 km/h
.
7/05/2013
www.oceancontrols.com.au
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