Handshaking Scanning with PCI DMM and SCXI

[Cimteker]

Hi,

I am trying to implement handshaking scanning with hardware that I have. Here's my setup:

My software : NI-DMM 2.5, NI-SWITCH 3.0.49161, NI-DAQmx 8.0.0f0, NI-VISA 3.4, VC++ 2005 Express.

My hardware : PCI 4070, SCXI1000, 2 SCXI1127, SH9MD-AUX cable and SCXI 1359 kit.

First I am trying to run the example called niSwitchDMMSwitchHandshaking.c. I am getting an error message that says:

"Sample trigger or trigger source cannot be set to external when the device is configured for SCXI control"

My setup uses PCI-4070 as a chassis communicator, but this is not something that I can change. How can I solve this?

Another related question is do I need to make any additional electrical connections? One of the functions sets trigger attributes to FRONT_CONNECTOR but the "Scanning Switch Modules" document explains that "AUX I/O can be used to control an SCXI chassis and to sent and receive triggers", and that would be my prefered setup. What do I need to do?

Thank you for your prompt help.

Jerry.

[JasonSmith]

When controlling the SCXI chassis through your DMM, the trigger input comes through pin 3 on the AUX I/O Connector, which correlates to the Aux Trigger In signal.  For your configuration, both parameters for the switch should be set to Rear Connector, the DMM Trigger should be set to Aux Trig 1, and the Measurement Complete Destination should be external.

When used in this configuration you should not need any additional wiring for the handshaking signals, but you will still need to make external connections for the signals themselves.

Jason S.
Applications Engineer
National Instruments

[Cimteker]

Thank your for your reply.

Are you sure that this can be done with my configuration? I have 2 SCXI-1127 cards and here's what I was told:

"There is no way to do handshake scanning with this hardware setup. What you would need is the PXI-1011 chassis.

These 1127 can only send its Advance Complete trigger to SCXI trigger “TTL 2”, available only in the PXI-1011. It cannot send their Advance Complete trigger the rear connector."

Thank you

Jerry.

[JasonSmith]

You are correct, I had missed this detail of the SCXI-1127's operation.  Since you are using a PCI-4070, it is not possible to use the PXI-1011 chassis with your current DMM.  The best solution I could recommend would be to use another device, such as a USB-1359 to control the SCXI chassis, then the AUX Connector on your DMM will be available to make the trigger connections needed for handshaking with the SCXI-1127 switch.  Keep in mind; however, that you will only be able to handshake with one of your switches using this method.  I believe that you are already working directly with another Engineer at NI, so I will allow him to assist you from this point forward.

NI Products: USB-1359 

Jason S.
Applications Engineer
National Instruments