Tektronix and Keithley

Hi,

We're using a 6485 attached to a Contec ethernet / GPIB adapter (RP-GPIB(FIT)GY - http://www.contec.com/product.php?id=1245 ). Every so often the 6485 will lock up: display freezes and it does not respond to any front panel buttons. To unfreeze it we need to do the following:

- disconnect the GPIB cable
- remove power cord
- wait approximately 10 minutes before applying power again

Anything else (including power cycling from front panel or momentarily disconnecting the power cord) leaves it in the same state it was.

Anyone else seen this? Unit was purchased last 6 months or so, I don't have it in front of me but I would say it's latest firmware. Same problem happens on a unit we purchased ~ 3 years ago. I cannot reproducibly cause the unit to fail, it happens randomly perhaps once every few weeks. We have no problem with other units connected through other GPIB interfaces.

I have let Model 6485 run over several days on GPIB for some applications and have had no hang ups.
I have not had any experience with GPIB to LAN conversion.
Is there a way you could monitor the SCPI commands and reading data going across the conversion?
If you could do this maybe it will give some clue as to where and why it hangs.

Hello, I have slightly different problem. My 6485 is connected via serial cable to pc with labview. I'm trying to speed up readings from ammeter (current rate is about 1 reading per 0.4-0.5 sec). I thought that reading speed is slow due interface speed, but than i changing the rs-232 interface speed from 9600b to greater value, the device hangs up and I have to turn off and turn it on. So, my questions are:
Will increasing interface speed cause increasing reading rate?
How to increase interface speed without device freezing? Maybe some other settings like parity, stop bits, flow control will help? Although I have tried different combinations already.

To increase the reading rate of the Model 6485 use the following commands.
:SENSE:CURR:NPLC 0.01
:SENSE:CURR:RANGE 1e-6
:SENSE:CURR:AVER:STAT OFF
:SYSTEM:AZER:STAT OFF
:TRIG:DEL 0.0

This will increase the measurement speed.
It only matters if sending back a lot of data will the bus matter for speed.

Long time to get back to this. We have the 6485 controlled externally through the digital trigger. The problem is reliably fixed by removing power, unplugging the external digital trigger then replugging both.