Interlock problem

Kai Zang kaizang at
Tue Oct 16 08:16:21 PDT 2012

Hi John, 

I did measurement between [0V, 1V] and [-1V, 0V]. Normally it should be OK, that's why I wonder something wrong with the machine. Right before this error message showed several times but last night it keeps showing.

Thanks for your reply! =D


Electrical Engineering
Stanford University

58 Dudley Ln, Apt 108B
Stanford University
California, USA, 94305
Tel: 650-561-5095
Email: kaizang at

----- Original Message -----
From: "John Shott" <shott at>
To: "Kai Zang" <kaizang at>
Cc: "micromanipulator6000" <micromanipulator6000 at>
Sent: Tuesday, October 16, 2012 7:30:53 AM
Subject: Re: Interlock problem


What voltage were you trying to use?  The B1500 has an external 
interlock cable that won't allow SMU voltages to exceed +/- 42 V unless 
the interlock is closed.  I only realized this recently ... Julie Segal 
pointed this out to me ...

We have ordered parts to attach magnetic proximity switches to the cover 
of the probe station so that the interlock will be satisfied when the 
probe station is closed (or mostly closed).  Unfortunately, while most 
of those parts will be shipped to us in the next couple of days, one of 
them won't arrive until the first week of Novemeber.

Were you trying to apply voltages higher than 42V, or were you seeing 
this error under all circumstances?



On 10/15/2012 10:18 PM, Kai Zang wrote:
> Hi all,
> Has any one of you encountered a problem of interlock problem? It said 'Interlock circuit is open. Interlock circuit must be closed for setting voltage source/compliance absolute value exceeding 42V'. And we cannot conduct any measurements at all.
> Thanks for your help in advance! =)
> Best,
> Kai
> -----
> Kai ZANG
> Electrical Engineering
> Stanford University

More information about the micromanipulator6000 mailing list