Experimental Physics and
Industrial Control System

The %c converter should do it, along with a 'width' number of expected characters (nnn in the example below). If this is to read an unknown number of bytes, then the 'nnn' quantity will result in a timeout to terminate the read. You would want to use @readtimeout to set some reasonable number for that timeout.
I've used this method for reading binary formatted scope waveforms where the number of bytes in the waveform is known a priori, but never for reading a block of unknown size. There does seem to be an as yet unresolved performance issue in streamDevice when the asyn port driver is linuxGPIB, in case that is your architecture. I ended up using a bare asyn record with DTYP=asynOctetCommandResponse to solve it, coupled with a subroutine record to strip off an un-needed header and perform a converison to multi-byte words.

> PrtScr {
>      InTerminator = "";
>      ReplyTimeout = 15000;
>      out "HARDCOPY START";

>      in "%nnnc";
           ^^^^

> }

  ---   rod.



Pavel Masloff wrote:

Hey Rod,

Which IN converter should I use in the protocol file of StreamDevice?
I have tried %u and it didn't work:

record(waveform, "$(P)$(R)file") {
    field(DTYP, "stream")
    field(SCAN, "Passive")
    field(INP, "@devTPS20xx.proto PrtScr $(PORT) $(A)")
    field(NELM, "500000")
    field(FTVL, "UCHAR")
}

PrtScr {
    InTerminator = "";
    ReplyTimeout = 15000;
    out "HARDCOPY START";
    in "%u";
}

L1 TPS2024B:file: Input
"BM╩7<00><00><00><00><00><00>6<04><00><00>(<00><00><00>@<01>..." does
not match format %u

On Mon, Apr 30, 2012 at 12:24 AM, Rod Nussbaumer <[email protected]

<mailto:[email protected]>> wrote:

   In principle, you should be able to read the binary data just as if
   you were receiving a binary formatted waveform. The EPICS waveform
   record will need to be set to an unsigned char data type. The trick
   will be to properly handle ending the transmission. Since your
   Python code seems to use a timeout to determine the end of the file,
   you could do that in streamDevice, too, by setting ' InTerminator =
   "" ' & setting some reasonable number for the 'ReadTimeout' in the
   protocol for the image file reader. Perhaps Dirk can confirm this.

   You will need to set the NELM field to something large enough to
   hold the largest image file that can be transmitted. I do not know
   how you could automatically get the image data from the waveform
   record into a file without some assistance from a host-based tool.

   Rod Nussbaumer
   ISAC Controls, TRIUMF
   Vancouver, Canada.


   Pavel Masloff wrote:

       Why can't I?
       In Hyperterminal (as well as in Python) you simply send a
       command and
       receive bytes, which you forward to a binary file. Sth like this:

       |import sys
       import os
       import time
       import serial

       # create target file
       print os.getcwd()
       f = open('hardcopy.png', 'wb')

       # configure the serial connection
       ser = serial.Serial()
       ser.port = 0
       ser.timeout = 0
       ser.baudrate = 9600

       ser.open()

       # configure the hardcopy settings
       cmd = ':HARDCOPY:FORMAT PNG;PALETTE NORMAL;PORT RS232;LAYOUT
       PORTRAIT;\
       PREVIEW 0;INKSAVER 0;COMPRESSION 0\n'
       a = ser.write(cmd)
       print "bytes sent: {:d}".format(a)

       # start hardcopy
       a = ser.write("HARDCOPY START\n")
       print "bytes sent: {:d}".format(a)

       # begin receiving data and writing to file
       total_bytes = 0;
       a = ser.inWaiting()
       while a>0:
            time.sleep(0.5)
            data = "">             total_bytes += a
            f.write(data)
            time.sleep(0.5)
            a = ser.inWaiting()
            sys.stdout.write(".")

       # close file and serial port
       sys.stdout.write("\n")
       f.close()
       ser.close()

       print "bytes read: {:d}".format(total_bytes)
       print "script completed"|


       Are you sure StreamDevice won't write the input to a waveform
       record?


       On Sun, Apr 29, 2012 at 7:47 PM, Mark Rivers
       <[email protected] <mailto:[email protected].edu>

       <mailto:[email protected].__edu

       <mailto:[email protected].edu>>> wrote:

           I don't think you can get the image into a waveform record
       from the
           scope with StreamDevice.  You would have to write another driver
           that does what you were doing with Hyperterminal and Python.
         You
           could perhaps use an SNL program for this.

           To display an image in BOY you use the Intensity Plot
       widget.  The
           waveform record is 1-D, but you tell the BOY widget the
       actual X and
           Y dimensions of the array.

           Mark

           __________________________________

           From: Pavel Masloff [[email protected]
       <mailto:pavel.masloff@gmail.com>

       <mailto:pavel.masloff@gmail.__com <mailto:pavel.masloff@gmail.com>>]

           Sent: Sunday, April 29, 2012 9:22 AM
           To: Mark Rivers
           Cc: EPICS Tech Talk
           Subject: Re: [Scopes] BMP image record??

           Is there any working example on how to get the image into a
       waveform
           record using StreamDevice? I haven't used the waveform
       record yet,
           reading up on this in the db reference manual, not that
           comprehensible :(

           Another question is how to read a waveform (image type) in BOY?

           Pavel

           On Sat, Apr 28, 2012 at 5:53 PM, Mark Rivers
       <[email protected] <mailto:[email protected].edu>

       <mailto:[email protected].__edu
       <mailto:[email protected].edu>><mailto:rivers@cars.__uchicago.edu
       <mailto:[email protected].edu>

       <mailto:[email protected].__edu

       <mailto:[email protected].edu>>>> wrote:
           If you can get the image into a waveform record, using
       streamDevice
           for example, then you can display that waveform as in image
       in EDM,
           CSS BOY, ImageJ or other applications.  You need to create a few
           other records that tell the client what the actual image
       dimensions are.

           It may be just as easy to implement reading the actual waveforms
           into waveform records, and display those with Cartesian plot
       widgets
           in your display manager.

           Mark

           __________________________________
           From: [email protected]
       <mailto:tech-talk-bounces@aps.anl.gov>
       <mailto:tech-talk-bounces@aps.__anl.gov
       <mailto:tech-talk-bounces@aps.anl.gov>><mailto:tech-talk-__[email protected]
       <mailto:tech-talk-bounces@aps.anl.gov>
       <mailto:tech-talk-bounces@aps.__anl.gov

       <mailto:tech-talk-bounces@aps.anl.gov>>>
           [[email protected]
       <mailto:tech-talk-bounces@aps.anl.gov>

       <mailto:tech-talk-bounces@aps.__anl.gov
       <mailto:tech-talk-bounces@aps.anl.gov>><mailto:tech-talk-__[email protected]
       <mailto:tech-talk-bounces@aps.anl.gov>

       <mailto:tech-talk-bounces@aps.__anl.gov

       <mailto:tech-talk-bounces@aps.anl.gov>>>] on behalf of Pavel Masloff
           [[email protected] <mailto:pavel.masloff@gmail.com>

       <mailto:pavel.masloff@gmail.__com
       <mailto:pavel.masloff@gmail.com>><mailto:pavel.masloff@__gmail.com
       <mailto:pavel.masloff@gmail.com>

       <mailto:pavel.masloff@gmail.__com

       <mailto:pavel.masloff@gmail.com>>>]
           Sent: Saturday, April 28, 2012 2:17 AM
           To: EPICS Tech Talk
           Subject: [Scopes] BMP image record??

           Hello again,


           As I mentioned earlier we are running a series of
       experiments with
           our high current switches. I have written simple support
       ("...with a
           little help from my friend" Dirk Zimoch) for the Tektronix
       TPS2000
           over RS232 using StreamDevice and ASYN, so now I can
       remotely arm
           the scopes, set its properties, save waveforms on to the CF
       card,
           etc. But...

           In order to not run back and forth and see if everything went OK
           (which is rather tiresome and time consuming), we need a
           confirmation from the scopes. I don't want to deal with the
           implementation of the waveform records for now, all I have
       got so
           far is that I save them on the flash card.
           As such a confirmation I see transferring the BMP (or PNG) image
           from the scope (sort of Print screen) on to the operator PC
       somehow.

           There is a special SCPI command "Hardcopy start". Which
       mimics the
           Print button on the scope's front panel. I have tried to
       transfer a
           BMP file via Hyperterminal (and Python script) and it worked out
           well (more or less).
           How could this be ported to the EPICS database from the IOC and
           client standpoint, so an operator could see the oscillogram
       on the
           screen and decide whether the experiment went well, so she
       will save
           the waveforms and move on to the next experiment?

           The image file is maximum ~ 46Kb (20Kb on average).
           Any thoughts?


           --
           Best regards,


           Pavel Maslov, MS
           Controls Engineer at Pulsed power Lab
           Efremov Institute for Electro-Physical Apparatus
           St. Petersburg, Russia

           Mobile: +7 (951) 672 22 19
           Landline: +7 (812) 461 01 01



           --
           Best regards,


           Pavel Maslov, MS
           Controls Engineer at Pulsed power Lab
           Efremov Institute for Electro-Physical Apparatus
           St. Petersburg, Russia

           Mobile: +7 (951) 672 22 19
           Landline: +7 (812) 461 01 01




       --
       Best regards,


       Pavel Maslov, MS
       Controls Engineer at Pulsed power Lab
       Efremov Institute for Electro-Physical Apparatus
       St. Petersburg, Russia

       Mobile: +7 (951) 672 22 19
       Landline: +7 (812) 461 01 01





--
Best regards,


Pavel Maslov, MS
Controls Engineer at Pulsed power Lab
Efremov Institute for Electro-Physical Apparatus
St. Petersburg, Russia

Mobile: +7 (951) 672 22 19
Landline: +7 (812) 461 01 01