AppendixC CommonQuestions
6023E/6024E/6025EUser Manual C-4 ni.com
24-bitc ounters (unlike the 16-bit counters on devices without the
DAQ-STC).
If you are using the NI-DAQlanguage interface or LabWindows/CVI, the
answeris no, the counter/ timer applications that you wrote previously will
not workwith t he DAQ-STC.You must use the GPCTR functions; ICTR
and CTR functions will not work with the DAQ-STC.The GPCTR
functions havethe same capabilities as the ICTR and CTR functio ns,p lus
more,but you must rewrite the application with the GPCTR function calls.
Iam using one of the general-purpose counter/timers on my device, but
Ido not see the cou nter/timer output on the I/O connector.What am I
doing wrong?
Ifyou are using the NI-DAQ language interface or LabWindows/CVI, you
mustconfigure the output line to output the signal to the I/O connector. Use
the Select_Signalcall i n NI-DAQto configure the output line. By
default,all timing I/O lines except EXTSTROBE* are high impedance.
Whata rethe PFIs and how do I configure these lines?
PFIsare programmable function inputs. These lines serve as connections to
virtuallyall internal timing signals. If you are using the NI-DAQlanguage
interfaceor LabWindows/CVI, use the Select_Signal function to route
internal signals to the I/O connector,route external signals to inter nal
timing sources, or tie internal timing signals together.
Ifyou are using NI-DAQ with LabVIEW and you want to connect external
signalsources to the PFI lines, you can use AI Clock Config, AI Trigger
Config,AO Clock Config, AO Trigger and Gate Config, CTR Mode
Config,and CTR Pulse Config advanced level VIs to indicate which
functionthe connected signal serves. Use the Route Signal VI to enable the
PFIl ines to output internal signals.
Caution Ifyou enable a PFI line for output, do not connect anyexternal signal source to it;
if you do, you can damage the device,the c omputer,and the connected equipment.
Whata rethe power-on states of the PFI and DIO lines on the I/O
connector?
Atsystem power-on and reset, both the PFI and DIO lines are set to high
impedance bythe hardware. This means that the device circuitry is not
activelydriving the output either high or low.However, these lines can have
pull-upor pull-down resistors connected to them as shown in Table 4-3, I/O
Signal Summary. These resistors weakly pull the output to either a logic
highor logic low state. For example, DIO(0) is in the high impedance state