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Message ID: 1628     Entry time: Sat Apr 9 12:30:15 2016
Author: Aidan 
Type: Summary 
Category: DAQ 
Subject: DAC back online for laser SLOW control: now via Acromag 

With the (intentional) demise of the VME crate, the slow controls for the laser were brought back online today. So far, only the controls for the laser temperature are running. However, if you run the LASER SLOW MEDM screen, the channels C3:PSL-ACAV_SLOWOUT and C3:PSL-RCAV_SLOWOUT are now active. 

To achieve this: I did the following:

1. Restored FB2 to the local network to allow for GUI interface to EPICS.

2. On the computer running the MODBUS IOC (, I created some channels in the DB that are "ai" channels with the names C3:PSL-A(R)CAV_SLOWOUT. There are some CALC channels that use these as inputs to convert to counts and then the output is sent to the approrpiate DAC register on the acromag unit via the modbus protocol.

3. So now any computer running EPICS on the local network can interact with the SLOWOUT channels

We connected BNCs up between the Acromag terminals and the SLOW IN BNC inputs on the front panel of the two NPRO controllers and double-checked that a requested voltage actually yields that voltage at the NPRO controller.


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