Hi,
I am trying to accomplish the following task:
I want to measure 11 PRT100 probes (5 wires) using one CR1000. For this I had to buy two additional TIM s and one AM16/32B multiplexer, yet i don't manage to make the connection between 2 TIMs, the logger and the multiplexer and the software does note cope with such measurements. I was told that I need to write a CR basic program, yet programming is not my forte. Please if anyone can help me with that I will be forever grateful.
Thank you
Are the probes 4 wires plus a screen connection? I am not sure what a 5-wire connection is otherwise?
I am sorry that Shortcut, to whioh I think you are referring, does not support PT100 sensors via the multiplexer, but connecting several sensors to an AM16/32 is feasible and quite common, in Europe. We can help you with a program once we know the exact sensor you have. Please also confirm which TIMs you have.
Yes the probes are PRT100 with 2reds, 2whites and 1black (screen) - the telescopic shape and thanks for your help...
OK to measure all the sensors on the AM16/32 you only need one of the 4WPB100 TIMs. Connect this to the logger as shown in figure 3 of the TIM manual.
As a test connect one of your sensors to the TIM module as show in the that manual using the two red wires for the top connections to the PRT and the two wire for the bottom two connection (I assume the same colour wire connects to the same end of the PRT).
Load the program below and check the values in the variable PRTTemp_C - you should have eleven identical temperature measurements from the single PRT. Note the is an edited program from one generated in Shortcut.
If OK now turn off the power and wire up the AM16/32 for the control lines and power as shown in Fig 3 in its manual with the multipexer set in 4-wire mode. C1 to Res and Clock to C2. Connect the equipotential ground back to analogue ground on the logger.
Connect the PRTs to the switched connections H1, L1 to the two reds and H2, L2 to the two whites and the black screen to the equipotential ground. For the common terminals connect the multiplexer back to the TIM module in place of your original PRT, i.e. COM H1 and COM L1 to the L on the TIM and 2H, in place of the red wires of your PRT and COMH2 and COML2 to G of the TIM and 2L in place of the white wires.
The power on and you should hear the multiplexer clicking once per minute. The eleven PRT readings should be updated in the PRTTemp variables 1..11.
That should work.
-----
'CR1000
'Created by Short Cut (2.8)
'Declare Variables and Units
Dim LCount
Public BattV
Public PRTRs_Ro(11), PRTTemp_C(11)
Units BattV=Volts
'Define Data Tables
DataTable(Table2,True,-1)
DataInterval(0,60,Min,10)
Average (11,PRTTemp_C(),IEEE4,False)
Maximum (1,PRTTemp_C(),IEEE4,False,False)
Minimum (1,PRTTemp_C(),IEEE4,False,False)
EndTable
'Main Program
BeginProg
Scan(1,Min,1,0)
'Default Datalogger Battery Voltage measurement BattV
Battery(BattV)
'Turn AM16/32 Multiplexer On
PortSet(1,1)
Delay(0,150,mSec)
LCount=1
SubScan(0,uSec,11)
'Switch to next AM16/32 Multiplexer channel
PulsePort(2,10000)
BrHalf4W(PRTRs_Ro(LCount),1,mV25,mV25,1,Vx1,1,2035,1,1,0,_50Hz,1.0,0)
LCount=LCount+1
NextSubScan
'Turn AM16/32 Multiplexer Off
PortSet(1,0)
Delay(0,150,mSec)
'Convert Rs/Ro to temperature x11
PRT(PRTTemp_C(),11,PRTRs_Ro(),1.0,0)
'Call Data Tables AND Store Data
CallTable(Table2)
NextScan
EndProg