Experimental Physics and
Industrial Control System

Hi, folks.  I'm seeing what might be a bug in the behavior of PVs in the
pyepics interface, or at the very least something inconsistent with
advertised behavior.

I'm trying to use the wait=True option to PV.put() to wait for process
completion, after which I want to log the put action.  Here's a basic
example:

#!/usr/bin/env python
>From epics import PV
pv = PV('T1:TEST-SYS_B')
for i in range(10):
    pv.put(i, wait=True)
    print pv.get()

However, what I'm consistently getting as output from the above is
something like the following:

0.0
0.0
2.0
3.0
3.0
4.0
6.0
6.0
8.0
9.0

Note that the output is not at all what is expected: on three out of ten
writes a pv.get() immediately following a pv.put(wait=True) fails to
return the newly updated value.  I see the same failures if I instead
set use_complete=True and check for put_complete==True before issuing
pv.get().

If the put() has actually completed, why is the get() still seeing the
old value?

Thanks in advance for any help or suggestions.

jamie.