Possible GPIB Configurations

[acreamer]

Due to a computer upgrade and re-organization, as well as new needs, we now need to modify/upgrade/revamp our GPIB system.

GPIB is the only option to interface with many of out instruments, and we use a combination of Labview and Matlab, running on Windows XP, to do so. We use two different computers to interact with equipment on portable racks. The racks can be moved between two different low temperature systems on opposite sides of the room. The computers are next to each other, and are a distance of ~5 m and 15 m from each fridge. Up to 15 different things can be controlled at any point on the GPIB network. We would like to be able to control each fridge area simultaneously and independantly(possibly from the same or different computers). Also, electrical isolation can be an issue, especially between 40 MHz and 50 GHz and we would like our system to be immune to any transmission along the lines of a signal in this regime. There seem to be many options to connect the instruments with GPIB, between USB, fiber optics, ethernet etc and we are looking for input as to what type of setup is going to best meet our needs, which will be cheapest, easiest, most versatile etc; we also would like to know what will equipment be needed to set it up. We have ruled out wireless as an option, because of reliability, and the working frequency of the signal. Thank you in advance,

~A

[Sammy Z]

Dear acreamer,

USB is definitely not an option. 

If you got to NI 488.2 help the following is listed as distance limitations for GPIB cabling:

To achieve the high data transfer rate that the GPIB was designed for, you must limit the number of devices on the bus and the physical distance between devices. The following restrictions are typical:

• A maximum separation of 4 m between any two devices and an average separation of 2 m over the entire bus.
• A maximum total cable length of 20 m.
• A maximum of 15 devices connected to each bus, with at least two-thirds powered on.

I would say the cheapest way would be to have your computers moved close to the low temp locations and have those 2 computers sync'ed together as far as timing.

You could also go with GPIB extenders:

https://www.ni.com/en-us/shop/model/gpib-140b.html

Please read the manual of the product.

Sincerely,

Sammy Z.