Trigger 2 equipments concurrently using GPIB

[KTChiam]

Hi,

I'm using 3 equipments controlled by GPIB interface. In one of the applications, I need to trigger 2 of the equipments to start testing at the same time (by issuing TEST command to both equipments). Is there a way to send a single command to multiple GPIB instruments or 'broadcast'? I know I can sequentially send 2 TEST command to both equipments separately, but this will cause delay to the latter equipment and affects the test result.

[Albert.Geven]

Look at the GET (group execute trigger) It is a signal on the gpib bus especially meant for triggering more intstruments

[Curt_C]

Hi,

If you are using the GPIB .NET library you can use the 'Board' object.

Use the 'Write' function to send the same command string to multiple devices in an 'AddressCollection'

if your using LabVIEW, you can use 'SendList'

http://zone.ni.com/reference/en-XX/help/371361E-01/lvinstio/sendlist/

Curt

[KTChiam]

Hi Curt,

I'm using Labview and unfortunately also VISA to access the GPIB. The reason is that the software needs to support both serial port and GPIB.So, using GPIB allows the software to be used without changes. Is there similar function with VISA?

Thanks.

KT

[Albert.Geven]

Hi

you can use the visa assert trigger function

or simply intermix gpib and visa calls it is not forbidden.

If you use visa you probably need to address the board not the device itself.

Asserts a software or hardware trigger, depending on the interface type. For software triggers, Default (0) is the only valid protocol. For VXI hardware triggers, Default (0) is equivalent to Sync (5). For PXI triggers, PXI: Reserve (6) and PXI: Unreserve (7) are the only valid protocols.

Details Examples

	VISA resource name specifies the resource to be opened. The VISA resource name control also specifies the session and class.
	protocol is the trigger protocol to use during assertion. This input accepts the following values. 0 Default 1 On 2 Off 5 Sync 6 PXI: Reserve 7 PXI: Unreserve
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	VISA resource name out is a copy of the VISA resource name that VISA functions return.
	error out contains error information. This output provides standard error out functionality.

VISA Assert Trigger Details

Software Triggers for 488.2 Instruments (GPIB, VXI, TCP/IP, USB)

This function sends an IEEE-488.2 software trigger to the addressed device, with the following bus-specific details:

• GPIB—VISA addresses the device to listen and sends the GPIB Group Execute Trigger (GET) message.
• VXI—VISA sends the Word Serial Trigger command.
• USB—VISA sends the trigger message ID on the bulk-out pipe.  

[KTChiam]

Hi Albert,

Thanks for your feedback. I'll try it out.

KT

[KTChiam]

Hi Albert,

Thanks for your feedback. I'll try it out.

KT