Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Tue, 8 Apr 2008 09:25:19 -0500

Hi Burkhard,

int32Driver.c is a simulated driver, so it does not do real I/O.  The int32Write and int32Read functions write and read the data from a private structure in the driver.

If you want a simple example of a VME register-based asynInt32 driver you can look at my driver for the Systran DAC-128V.  It is here:

http://cars.uchicago.edu/software/epics/dac128V.html

Note that the source code for that driver is fine, but the documentation is out of date, it still refers to MPF, which predated of asyn.

Here is the asynInt32 write function in that driver:

static asynStatus writeInt32(void *drvPvt, asynUser *pasynUser,
                             epicsInt32 value)
{
    drvDac128VPvt *pPvt = (drvDac128VPvt *)drvPvt;
    int channel;
    pasynManager->getAddr(pasynUser, &channel);
    if(value<0 || value>pPvt->maxValue || channel<0 || channel>pPvt->lastChan)
        return(-1);
    pPvt->regs[channel] = value;
    asynPrint(pasynUser, ASYN_TRACEIO_DRIVER,
              "drvDac128V, port %s, wrote %d to channel %d\n",
              pPvt->portName, value, channel);
    return(0);
}

Mark

________________________________

From: [email protected] on behalf of Burkhard Kolb
Sent: Tue 4/8/2008 8:49 AM
To: '[email protected]'
Subject: Example for VME reg-based port driver for asyn on Linux?

Hi

I'm in the process of converting applications from VxWorks to Linux.
I have a multitude of VME boards with write/read registers (no
interrupts). On VxWorks I usually have built subRecords to access the
registers on the boards.
Now we use Concurrent single board cpus in VME (running linux) where the
use of mapping registers is restricted due to the large address space of
the cpus. So I would like to map the individual boards in an orderly
fashion via some register-board-base-addr call and then use for instance
asyn int32 support.
I have looked in the example int32Driver.c but can't see where the real
I/O is done?

Does anyone have some real example? Or is this sort of overkill?

Many thanks, Burkhard
--
Dr. Burkhard Kolb
KP1 / GSI
E-Mail: [email protected]
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System