Experimental Physics and
Industrial Control System

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>> 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>]

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

   <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>>]
   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