VXi VT1529A/B 사용자 설명서
164 Advanced Programming with the VT1529B
For example, the existing SCPI commands to measure thermocouples with
a VT1508A SCP and the VT1422A are:
a VT1508A SCP and the VT1422A are:
SENS:REF THER,5000,(@108)
Sense the reference temperature
on channel 108 using a 5k
thermistor
on channel 108 using a 5k
thermistor
SENS:FUNC:TEMP TC,J,(@109:111)
Indicates channels 109 through
111 are type J thermocouples
111 are type J thermocouples
SENS:REF:CHAN (@108),(@109:111)
Specifies channel 108 as the
isothermal reference for
channels 109 through 111
isothermal reference for
channels 109 through 111
ROUT:SEQ:DEF (@108:111)
Sets scan list to include the
reference and the thermocouples
reference and the thermocouples
INIT
Start scan
To measure thermocouples using the VT1529B and VT1586A using the
new commands:
new commands:
SENS:REF:POST THER,5000,(@10000),(@10001)
Specifies that the reference
thermistor voltage is on channel
10001 and its excitation voltage
is on channel 10000
thermistor voltage is on channel
10001 and its excitation voltage
is on channel 10000
SENS:FUNC:TEMP:POST TC,J,(@10003:10005)
Indicates channels 10003
through 10005 are type J
thermocouples
through 10005 are type J
thermocouples
SENS:REF:CHAN:POST (@10001),(@10003:10005) Specifies channel 10001 as the
isothermal reference thermistor
for channels 10003 through
10005
for channels 10003 through
10005
ROUT:SEQ:DEF (@10003:10005,10001,10000)
Sets scan list to include the
thermocouples, the reference
thermistor and excitation voltage
thermocouples, the reference
thermistor and excitation voltage
INIT
Start scan
Similarly, the VXIplug&play call to read the FIFO data changes from:
hpe1422_readFifo_Q(vi, 1000)
Read 1000 readings
to
hpe1422_readFifoPost_Q(vi, 2, 0, 65024, f64_array)
Read 2 scans of data,
post-convert to EU, no extra
data in FIFO from algorithms
post-convert to EU, no extra
data in FIFO from algorithms
Strain Measurements
With the VT1529A, the excitation voltages are measured once prior to the
start of scanning (INITiate:IMMediate command). The measured value is
then sent to the DSP for use in the on-the-fly EU conversions. Therefore, for
long tests, for the best possible accuracy, the excitation supply must be both
long-term and short-term stable.
start of scanning (INITiate:IMMediate command). The measured value is
then sent to the DSP for use in the on-the-fly EU conversions. Therefore, for
long tests, for the best possible accuracy, the excitation supply must be both
long-term and short-term stable.
With the VT1529B, the excitation voltage can be measured during each scan
and the VXIplug&play driver can use updated measurements for the
conversions. This provides better accuracy and uses a less expensive
excitation supply.
and the VXIplug&play driver can use updated measurements for the
conversions. This provides better accuracy and uses a less expensive
excitation supply.