Working in the field, technician gets NaN values for water level and 0.0 for temperature when operating the CS450 pressure sensor and CR1000 datalogger. Using PC200W to view connection. We have checked the connections between the cables and that the correct port is being used. The logger recognizes the gauge (portStatus goes true when scanning), but the readings do not change from NaN and 0.0.
Here is the program being used:
'CR1000
'Created by Short Cut (2.8)
'Declare Variables and Units
Public BattV
Public CS450Data(2)
Alias CS450Data(1)=Lvl_m
Alias CS450Data(2)=Temp_C
Units BattV=Volts
Units Lvl_m=meters
Units Temp_C=deg C
'Define Data Tables
DataTable(WaterLvl,True,-1)
DataInterval(0,2,Sec,10)
CardOut(1,-1)
Average(1,Lvl_m,FP2,False)
EndTable
DataTable(WaterTmp,True,-1)
DataInterval(0,1,Min,10)
CardOut(1,-1)
Average(1,Temp_C,FP2,False)
EndTable
'Main Program
BeginProg
Scan(2,Sec,1,0)
'Default Datalogger Battery Voltage measurement BattV
Battery(BattV)
'CS450/CS455 Pressure Transducer measurements Lvl_m and Temp_C
SDI12Recorder(Lvl_m,7,"0","M1!",1,0)
Lvl_m=Lvl_m*0.70307
'Call Data Tables and Store Data
CallTable(WaterLvl)
CallTable(WaterTmp)
NextScan
EndProg
I'm getting similar readings connecting a CR510 with CS450.
The temp reading is random (usually increasing), but -INF for the pressure reading. I moved the white wire from CS2/P3 to CS1, and the red wire is on 12v.
How hard can this be?
There are a couple reasons why you may not acquire readings from an SDI-12 sensor:
1. Sensor signal wire is not attached to the Control Port the datalogger is programed to use.
2. Sensor power wire is attached to SW12V instead of 12V. SW12V can be used, but the SW12() instruction must be used in the program to switch the 12V on and off.
3. The sensor may have been assigned a different address. Sensors leave the factory with an address of 0, but if this has been changed, the SDI12 instruction used in the datalogger must also reflect this change. The following instruction will work if your sensor is attached to C7, has power, and has the address of 0:
SDI12Recorder(Lvl_m,7,"0","M1!",1,0)
If the sensor address had been changed to, say, 5, then the
correct instruction would look like this:
SDI12Recorder(Lvl_m,7,"5","M1!",1,0)
The NAN for the first value means that the logger isn't getting anything back that it recognizes, so it just populates that first value with a NAN. Your program has the white wire on c7, and an address of 0. Check all of your connections, particularly the red wire in 12V and the white wire in c7, also make sure that you have taken the cap of the vent tube. In PC200W from the clock/program tab highlight your datalogger in the list on the left, click on the datalogger heading at the top of the page and choose terminal emulator from the pick list, click on open terminal,
hit the enter button until you get the cr1000 prompt, enter 'SDI12', choose control port 7, now you are in a transparent mode and can talk directly to the sensor and see if it will respond and is addressed correctly, enter '?!', the sensor should respond with its address which should just be 0, if it responds with another address you can change it by entering in the old address first then A, and the new address, ie, if it is 1 and you want to change it to 0 enter '1A0!' and it should now respond with a 0. If you don't get any response and you have checked all the connections you could try stopping the program in file control and then going through the process again, or just slowing down the scan rate and trying this process again. You are scanning at 2 seconds and there is alot of traffic on the line, so it would be a good idea to slow it down while trying to talk through to the sensor in transparent mode. The cs450 manual has a section on the transparent mode, and also the cr1000 manual covers this topic. It is a good trouble shooting technique for issues like you are having.