I'm new to using DataTakers.

We have new DT85M and DT80M [with V9.16]

We have devices that measure both strain (full bridge) and temperature from the one power supply.

Wiring cores for the sensors:
Screen = "Terminated at computer"
Pink = 5v dc Power
Grey = 0v
Green = Strain +ve
White = Strain -ve
Blue = Temperature

We assume the wiring for a DT80M to accept these inputs would be (over 2 channels):

1. '* = Pink = 5v dc Power '+ = Green = Strain +ve '- = White = Strain -ve '# = Grey = 0v

2.'+ = Blue = Temperature
[connect between # and -]? or use deX option for "shared terminal Voltage (+/#)?

Note that the sensor requires 5V excitation.
Can the DataTaker be programmed to output 5V excitation? or will we need to provide external 5VDC for excitation?

As temperature calibration is simply given as 10mV/°C with full range as [-40 to +85°C], I assume we log that channel as a simple voltage and apply a scaling multiplier.

How can we program the DT80M such that a data point is sampled each minute, with only the Median of the data being recorded at hourly intervals?
I see that others on the forum have found that DataTaker lacks a "median" function. Are there any (fairly simple) workarounds for this? if not -- we will need to calculate hourly Average instead.

Any help/tips/guides or program snippets greatly appreciated.

Peter

Hi Peter,

The wiring configuration is correct on channel 1, while on channel 2 you should connect grey wire to - or #.
If you choose - then you can use 2V or if you choose # then use 2+V (then apply a scaling to convert it to temperature).

However since dataTaker can't provide you with 5V excitation, you need to use an external excitation.
Please check Part O - Sensors and Channels; ANALOG CHANNEL section and BRIDGE sub-section from DT8x User Manual:

• 6 Wire BGV inputs, you may use this configuration when using 5V external excitation
• 4 Wire BGV inputs, you may use this configuration when using dataTaker excitation (4.5 V)

Unfortunately median function is not available in the logger.
There is another long way to obtain median, I will give you an example of 5 values median:

BEGIN"MEDIAN"
1..5CV=0
98..99CV=0

RA1M
5CV(W)=4CV
4CV(W)=3CV
3CV(W)=2CV
2CV(W)=1CV
REFT(=1CV)
99CV(W)=99CV+1
IF(99CV==5){99CV=0 GB}

RB HB
IF(1CV>2CV){98CV=2CV 2CV=1CV 1CV=98CV}
IF(2CV>3CV){98CV=3CV 3CV=2CV 2CV=98CV}
IF(3CV>4CV){98CV=4CV 4CV=3CV 3CV=98CV}
IF(4CV>5CV){98CV=5CV 5CV=4CV 4CV=98CV}
97CV(W)=97CV+1
IF(97CV==4){97CV=0 HB XC}

RCX
3CV("Median")

LOGON
END

If you have 60 values, then you can have 59 variable porting on schedule A and 59 conditional statements on schedule B, 99CV and 97CV must make a loop for 59 times.

Best regards,
Rudy Gunawan