Control Alicat PC through Labview

[tam_2407]

I see, thanks. I try a kd scientific pump through hyperterminal and have the same issue (no communication). The Kd pump use modular telephone connector, so I cut open a db 9 cable and rewire them to a telephone cable: TxD (pin3) to receive, RxD (pin2)to transmit, and GND (pin5) to ground. The rest is left unwired. Is it correct?

 here are the screens of hyperterminal for the pump:

                 

[tam_2407]

Hi DigitalMan,

Thank your for your suggestion. I bought the cable, so I don't know and hope that the wiring is correct. I  follow the manual step by step because I really have no idea what I am doing. I change the serial port set up in both Windows and MAX to 19200-8-N-1 (for the pressure controller),  but still nothing happens.

Tam

[AnalogKid2DigitalMan]

Let's presume the cable wiring is correct. Just make sure they are firmly seated at the connections on both ends.

Have you checked what the communication settings are set to within the controller itself. Check them and reset them to the default values listed in the manual if needed.

You need to also verify set these parameters up just in Hyperterminal to match the controller settings, not in MAX, and never tried to see what effects happen if changed in Windows COM settings.

Dumb question- is the controller powered ON whenever you try to communicate (yes, I have seen this before).

-AK2DM

[Dennis_Knutson]

And it might be wise to do a serial loopback test. Short pins 2 and 3 at the pc and see if whatever you type is echoed back.

[tam_2407]

Hi DigitalMan,

The communication settings in the controller can not be changed, except alternating among Analog, Series, and Local control. The controller was used before with the 19200-8-N-1 setting, so I am pretty sure that it still is in the device. I put in the matched setting in Hyperterminal as well. The device is on and in Series control.

Tam

[tam_2407]

oh you are right, there is no echo back when I connect pin 2 and 3. What should I do?