GPIB-Invalid Character and Query Unterminated

[ckryan]

Hi,

Recently, I just upgraded Fluke-Hart Scientific Calibration Bath from 7321 to 7040. Other equipment including power supply (Agilent N6700B) and sourcemeter (Keithly 2400) are used together with the bath for automation data acquisition by NI LabView. The old bath 7321 worked perfectly well but the new bath 7040 is giving me some hiccups. I could not paired to use 7040 bath with the power supply and sourcemeter. I could only remote controlling one at a time, LabView control 7040 bath or LabView control other equipment. But, never all at a time. The error message I got from NI MAX by sending *IDN? is “Invalid Character- 101” and "Query Unterminated".

If I plug off the 7040 bath, I could "*IDN?" and MAX could explore and fiind my power supply and sourcementer. The plug off here means physically detach the GPIB connector from the connector. If I just powered off the 7040 bath but with the GPIB connector plug on, I still getting the same message. Weird to me. If I plug off power supply and sourcemeter by connecting solely to the 7040 bath with MAX, it worked with no issue. If I connect all 3 equipment together, MAX could only discover bath 7040 but not for power supply and sourcemeter.

In summary:

A: Fluke Calibration Bath 7040

B: Agilent's power supply and Keithly's 2400

MAX could discover A.

MAX could discover A only (but sometimes work intermittently) if A+B

MAX could discover B only if A's GPIB connector totally plugged off

I am using the latest MAX 4.7.2f0.

Thank You

[smercurio_fc]

Have you checked your cables? Have you tried other cables? Have you tried moving cables around to see if the problem follows a cable?

[ckryan]

I have tried swapping the cables. Still the same issue 😞

[ckryan]

Anyone can help me on this? Any other solutions for me to try?

[Albert.Geven]

Just some ideas

Do you have different addresses for all the instruments or is there a double?

Also some simpler/older instruments don't like fast busses so change the bus timing of the gpib interface to 5 microseconds

And at last uncheck auto parallel polling.

[ckryan]

---

@Albert Geven wrote:

Just some ideas

Do you have different addresses for all the instruments or is there a double?

Also some simpler/older instruments don't like fast busses so change the bus timing of the gpib interface to 5 microseconds

And at last uncheck auto parallel polling.

---

Hi Albert,

All equipment with different addresses. I have changed the bus timing to slower one and also unchecked the auto parallel polling. Same issue.

Could it be the spoil of the instrument GPIB card? It is a brand new calibration bath and don't think Fluke will give me a DOA part.

[JÞB]

Check out section 10.2 of the manual.  Some of these devices can be a bit painful and you seem to have a device that is NOT compliant to the IEEE 488 standard.  BTW it will never respond to *IDN? and Probably does bad things that IEEE 488 forbids when it receives the "Unknown" command. 

The odds are good that You may need to use the 488 drivers rather than VISA to set the mode for writes to 1 or 3 to set EOI on <CR> to terminate the queries the way the instrument expects (or just use the serial interface if the device won't play nice on the GPIB)  Unfortunatly, there are some bad pieces of gear out that that won't play nice.

The Yokogawa 7651 is notorious for hanging a GPIB bus in response to a *IDN? too.  Requiring a hard reset of the instrument before it would release handshaking lines.

[Omar_II]

Try sending a GPIB IFC command in between sending commands to 'A' and 'B'

I had an instrument that after talking to it I could not talk to any other instrument on the GPIB bus.

But if I sent the IFC command to the GPIB card before switching to communicate to the other instruments I did not have any problems.

This instrument would also cause the VISA Find function to report back listeners on all 32 GPIB addresses!

Really messed up my routines to search out instruments that are on my system. 

[ckryan]

---

@Omar II wrote:

Try sending a GPIB IFC command in between sending commands to 'A' and 'B'

I had an instrument that after talking to it I could not talk to any other instrument on the GPIB bus.

But if I sent the IFC command to the GPIB card before switching to communicate to the other instruments I did not have any problems.

This instrument would also cause the VISA Find function to report back listeners on all 32 GPIB addresses!

Really messed up my routines to search out instruments that are on my system. 

---

Hi, How do I send the GPIB IFC command? Help...

[JÞB]

---

@ckryan wrote:

---

@Omar II wrote:

Try sending a GPIB IFC command in between sending commands to 'A' and 'B'

I had an instrument that after talking to it I could not talk to any other instrument on the GPIB bus.

But if I sent the IFC command to the GPIB card before switching to communicate to the other instruments I did not have any problems.

This instrument would also cause the VISA Find function to report back listeners on all 32 GPIB addresses!

Really messed up my routines to search out instruments that are on my system. 

---

Hi, How do I send the GPIB IFC command? Help...

---

First, Have you been able to get a response from any supported query?  (*IDN?) still won't work.