VXi VT1422A 사용자 설명서

The steps for measuring temperature with the VT1529B and VT1586A 
should, again, be familiar. If a controlled temperature isothermal block is 
used, the command sequence is identical, except for the :POST keyword 
being added to some commands. Otherwise, the isothermal block 
temperature needs to measured, the major difference being that it is 
necessary to measure the excitation voltage, thermistor output voltage, and 
thermocouple voltage instead of just the thermistor and thermocouple voltage. 
This is because the VT1529B with VT1586A excites the thermistor with the 
excitation supply voltage that is provided instead of a calibrated current.

The thermistor measurement channel must be associated with its excitation 
voltage measurement channel as well as associating each thermocouple to 
the thermistor. The excitation voltage and thermistor measurement channels 
must be part of the scan list. Figure 5-7 shows the sequence of 
VXIplug&play driver calls to configure and scan thermocouple channels 
using the new functionality.

Periodic Calibration

Retrieve readings from

FIFO and/or CVT

Trigger event for each pass

through Scan List

Set up Trigger System to scan

temperature channels

Set up the analog input Scan List

Set up thermistor measurement

To convert readings to

Engineering Units of temperature

hpe1422_cmd(vi, "SENS:FUNC:TEMP:POST TC,

,(@

)");

hpe1422_cmd(vi, "SENS:REF:POST THER,5000,(@

),(@

)");

hpe1422_cmd(vi, "ROUTe:SEQuence:DEFine (@

,

),

hpe1422_cmd(vi, "TRIG:SOURce 

");

Similarly with TRIG:COUNt, ARM:SOURce, TRIG:TIMer

Set up Sample Timer for best
channel-to-channel scan rate

Initiate Trigger System

hpe1422_cmd(vi, "SAMPle:TIMer 40e-6");

hpe1422_cmd(vi, "INITiate:IMMediate");

hpe1422_cmd(vi, "*TRG");   (if TRIG:SOUR HOLD set)
EXTernal trig, TTLTRGn signal, or TRIG:TIMer

hpe1422_readFifoPost_Q(vi, , , 

, 

&rdgs_array);

Set Input Filter on VT1529B

hpe1422_cmd(vi, "INPut:FILTer:FREQuency 

");

Must include thermistor and excitation voltage channels.

hpe1422_cmdInt32_Q(vi, "*CAL?", &result);
hpe1422_cmdInt32_Q(vi, "CAL:REM? (@

)", &result);

hpe1422_cmd(vi, "INPut:FILTer:STATe 

");

hpe1422_cmd(vi, "TRIG:IMM");

Associate TC channels to

hpe1422_cmd(vi, "SENS:REF:CHAN:POST (@

),(@

)");

thermistor

(@

)");