acq400_hapi: acq400 Host API

A Python module to connect to remote hosts.

Documentation

Installation

Clone/update latest version from GitHub, then install in-place using pip. Dependencies listed in requirements.txt will be automatically installed if needed:

$ git clone https://github.com/D-TACQ/acq400_hapi
$ cd acq400_hapi
$ sudo pip3 install -e .

This creates a system-wide link to the local folder so that Python knows where to find pysf on your system. Then whenever desired, run git pull in the source folder to update from git, no further installation step required.

Usage

import acq400_hapi

How it works

The Acq400 class nails up a socket connection to all the site servers at 4220+s, as well as running a status monitor thread on 2235 and allowing access to post-shot data on 53000+ch.

Each knob on the site is presented as a property of the connection, so that simple bash-script-like syntax can be used.

NOTE on Name Service: HAPI uses regular DNS for name resolution. Ideally your UUT has a DNS name that matches the hostname. Check by pinging:

ping acq2106_123

If that works, you have DNS. If it doesn't, well HAPI will work with a raw IP address, but it's much clearer to set up a "local DNS". All our examples use the convention hostname IS dnsname.

The "local DNS" doesn't have to be full DNS subsystem, all you need is to set the name mapping in your system's hosts file:

Linux : /etc/hosts/
Windows : C:\Windows\System32\Drivers\etc\hosts

Running a session interactively while a test loop is running:

>>> import acq400_hapi
>>> uut = acq400_hapi.factory("10.12.132.22")
>>> uut.s1.shot
'348'
>>> uut.s1.shot
'348'
>>> uut.s1.shot
'349'

The goal is to make it easy to remote-script multiple uut's:

>>> import acq400_hapi
>>> uut1 = acq400_hapi.factory("acq1001_144")
>>> uut2 = acq400_hapi.factory("acq1001_145")

>>> for ii in range(0,10):
...    c1 = uut1.s1.SIG_SAMPLE_COUNT_COUNT.split(" ")[1]
...    c2 = uut2.s1.SIG_SAMPLE_COUNT_COUNT.split(" ")[1]
...    print("%s %s" % (c1, c2))
11078689363247 11078689363247
11078689363247 11078689363247
11078739404360 11078739404360
11078739404360 11078739404360
11078739404360 11078789398809
11078789398809 11078789398809
11078789398809 11078789398809
11078839399330 11078839399330
11078839399330 11078839399330

...and yes, these are EPICS PV's, so we could use capy. But, this way, it's all vanilla Python, no other installs required.

Knob names

SIG:SAMPLE_COUNT:COUNT are auto converted to valid python identifiers:
SIG_SAMPLE_COUNT_COUNT

You can enumerate all the knobs with:

>>> uut.s0.help()
..
>>> uut.s6.help()

Help also takes a regex:

>>> uut.s0.help(*COUNT)

Example:

>>> import acq400_hapi
>>> uut = acq400_hapi.factory("10.12.132.22")
>>> for f in uut.s0.help('.*FREQ'):
...     uut.s0.get_knob(f)
...
'SIG:CLK_EXT:FREQ 25007219'
'SIG:CLK_MB:FREQ 50012464'
'SIG:CLK_S1:FREQ 50010624'
'SIG:CLK_S2:FREQ 0'
'SIG:EVT_EXT:FREQ 0'
'SIG:EVT_MB:FREQ 0'
'SIG:EVT_S1:FREQ 0'

Speed

The Acq400 class can be fairly slow to instantiate (imagine an ACQ2106 with 6 sites populated), but once the connections are nailed up, then control links are fast. The use case is to set up the connection once, then operate over long periods.