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Entry  14 Jan 2004, Razvan Stefan Gornea, , Access to hardware in the MIDAS framework 
    Reply  14 Jan 2004, Stefan Ritt, , Access to hardware in the MIDAS framework 
       Reply  16 Jan 2004, Razvan Stefan Gornea, , Access to hardware in the MIDAS framework frontend.cmeterdev.c
          Reply  17 Jan 2004, Stefan Ritt, , Access to hardware in the MIDAS framework 
Message ID: 7     Entry time: 16 Jan 2004     In reply to: 6     Reply to this: 8
Author: Razvan Stefan Gornea 
Topic:  
Subject: Access to hardware in the MIDAS framework 
The multimeter device is indeed to simple to use MIDAS but I am just trying 
it as a learning experience. The DAQ system to develop involves VME crates 
and general purpose I/O boards. The slow control part, especially accessing 
the I/O boards seem to me more complex then the VME access. I want to 
understand very well the "correct" way of using the MIDAS slow control 
framework before starting the project.

I chose the second method and created a meterdev.c driver (essentially a 
copy of the nulldev.c) where I changed the init. function and the get 
function. I am not sending a "INIT ..." string because for this device it 
is useless. In the get function I send a "D" and read my string. I changed 
the frontend of the example to have a new driver list (in the first try I 
eliminated the Output device but the ODB got corrupted, I guess the class 
multi needs to have defined output channels). The output channel is linked 
with nulldev and null (I guess this is like if they would not be present).

The result is strange because the get function is called all the time very 
fast (much faster then the 9 seconds as set in the equipment) and even 
before starting the run (I just put the flag RO_RUNNING).

Thanks for any help
Attachment 1: frontend.c  2 kB  | Show | Show all
Attachment 2: meterdev.c  6 kB  | Show | Show all
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