Triggering multiple Keithley 2700's with one 2602 current source

[alarso]

Hello,

I am trying to use the external trigger of a current source (Keithley 2602) to simultaneously trigger a voltage measurement in multiple Keithley 2700 multimeters. I have split the trigger output of the current source in order to send the trigger signal to both multimeters. When only one trigger link is connected to one multimeter, I can measure the voltage. However, when I connect both trigger links, I cannot measure the voltage in either multimeter since I obtain an error "-268 runtime error". This seems to be more of a hardware than a software issue, since the same labview code works when one trigger is connected, but doesn't when both are connected.

Is it possible that the current from the external trigger is too low when divided into two?

Many thanks for the help,

Alex

[Minions]

Umm, Not sure that you have the system wired correctly if you are referring to a divide into two.  The TSP-Link is meant to be a daisy chained equipment link with the previous instrument talking into the input and the following instrument listening on the output.  The other issue might be your connecting cable.  It mentions using cable lengths less than 3 meters between TSP-Link devices.  If you swap the two cables, does the first 2700 instrument stop working?

[alarso]

Thanks for the quick reply. The cabling is indeed not daisy-chained, but the output of the current source is split into the trigger input to both multimeters. I did this in order to be able to simultaneously measure the voltage in both multimeters according to the trigger of the current source. Is this not possible?

Each cable works well when only one is plugged in, but as soon as I plug both in, none of the cables seem to work. So when both trigger links are connected, none of the 2700s measure anything.

[Minions · Accepted solution]

Each TSP-Link instrument works as a repeater.  As such data communications need to be setup similar to RS-232 (one-to-one) and not RS-485 (one-to many).  See Page 31 of the manual.

[alarso]

Ah I see, that's why it wasn't working then. Thanks!

But then if I daisy-chain them together, they won't be triggered simultaneously right?

[cymrieg]

Only the 2600 has TSP-Link - the 2700's don't

They both have digital (TTLS) triggers in & out

So I would

 - connect one dig out on 2600 to one 2700

 - different dig out on 2600 to the other 2700

[alarso]

That worked perfectly, thanks so much!