The ejector commands will be synchronized with the current chunk counter value.

The work flow for the ejector module from Scorpion perspective is as follows:
 

1. The frame is captured by camera, retrieved by Scorpion, and inspection is done.
2. After frame is grabbed a tool or script extracts the chunk counter from the frame
3. Based on inspection results the tool/script generates data matrix for the ejector device
4. The tool/script sends the generated data to the driver. The data sent must refer to the chunk counter position forward by at least 1 frame (frame length = height / Lines per trigger). When frame is captured the real chunk counter in the driver will be positioned at the end of that frame (i.e. the difference between counter embedded in the image and the current value will be size of one frame in chunks) therefore commands must be sent for the "future" chunk counter positions.
5. Goto 1

Calculate conveyor length

Conveyor length should be measured in chunk counter units and should not exceed 10000 (e.g. if lines per trigger is set to 20 then it will be equal to 200 000 image lines).
Snippet below shows how to calculate conveyor length of 2.3 frame lengths:

camera = GetCamera("0")
lineCounterResolution = camera.getProperty("LineCounterResolution")
imageHeight = camera.height
linesToEjector = int(imageHeight * 2.3)/lineCounterResolution

Extract Chunk Counter From Image

Each frame will have a chunk counter embedded as the 1st 3 bytes of the image (3 pixels for B/W and 1 pixel for color).
Snippet below shows hot to extract chunk counter:

startIndex = ejectorModulePlugin.GetEjectorModule().GetImageLineCounter(Image)

Ejector data is sent via driver. Call setProperty method for camera with following parmeters. The property name must be a formated string. The format is as follows:

EjectorLine $chunkCounter $data $callback $mask

where:

$chunkCounter - must be a chunk counter value for which data for the ejector device will be sent. Integer value (example: 7238)

$data - is 4 byte hex formated data for the ejector device. It is represented as hex string of length 8 chars (Example: 010AFFFF). This means, that 4 ports are supported. All port values are interpreted left to right (in the example above - port 0 will have value 01, port 1 = 0A, etc.). Each bit in the bytes represent 1 output for the ejector device.

$callback - 0/1 - one character for callback to Scorpion when ejector command is executed - OPTIONAL

$mask - 4 byte hex bitmask for which bites in data to use - OPTIONAL

Example 1: Set ejector output lines to a defined value when chunk counter = 7238:

camera.setProperty("%s %d %s" % ("EjectorLine", 7238, "010AFFFF"), 0)

Example 2: Set ejector output lines to a defined value when chunk counter = 7238, use two bits only by mask:

camera.setProperty("%s %d %s 1 %s" % ("EjectorLine", 7238, "00000001" "0000003"), 0) #uses 2 last bits only

camera.setProperty("%s %d %s 0 %s" % ("EjectorLine", 7245, "00000000" "0000003"), 0) #uses 2 last bits only

Example 3: Activate all ejector outputs after conveyor moves 2.3 frames:

dword = 0xFFFFFFFF
startEjector= startIndex + linesToEjector
for i in range(startEjector, startEjector + (imageHeight / lineCounterResolution)):
# send line to a camera driver
camera.setProperty("%s %d %.8X" % ("EjectorLine", i, dword), 0)

Ejector Static Mode

In static mode ejector continuously transmits the same eject command. To activate static mode use EjectorStaticMode property:

camera.setProperty('EjectorStaticMode', 1)

To set static mode ejector command call setProperty for camera in following format:

EjectorStaticCommand $data

• $data - is 4 byte hex formatted data for the ejector device.

Example 4: Activate Static Mode

camera.setProperty('EjectorStaticCommand EFEFEFEF', 0)
camera.setProperty('EjectorStaticMode', 1)

Example 5: Generate ejector pulse and process ejector command callback

def SetEjectorPulse():
  '''
  sets ejector pulse in Basler driver
  we requests a command callback for first line set
  '''
  pixelsize = GetFloatValue('Cal.PixelSize_x')
  ejectdist = GetFloatValue('ProcessSetup.EjectorDistance')
  pulselen  = GetFloatValue('ProcessSetup.EjectorPulseLength')
  start     = GetIntValue('Results.ChunkCounter')
  x         = GetFloatValue('Results.TopCenter_x')

  camera=GetCamera("0")
  lineCounterResolution=camera.getProperty("LineCounterResolution")
  if lineCounterResolution==None:lineCounterResolution=1

  ejectpos = start+int((ejectdist+x)/pixelsize/lineCounterResolution)
  length   = int(pulselen/lineCounterResolution/pixelsize)

  if not GetBoolValue('System.CameraSimulation'):
    prop0 = '%s %d %s' % ('EjectorLine',ejectpos,'00000001 1 00000001')
    prop1 = '%s %d %s' % ('EjectorLine',ejectpos+length,'00000000 0 00000001')
    #print '--->> SetEjectorPulse:  %s   %s' % (prop0,prop1)
    camera.setProperty(prop0, 0)
    camera.setProperty(prop1, 0)

 #add the command to send to PLS on command callback
 rs232queue[ejectpos]=('rs232cmd',GetStringValue('Results.RS232'))

def Handle_System_CameraCommand(Camera,Cmd,Params):
  #
  # Camera = VT_BSTR
  # Cmd = VT_BSTR
  # Params = VT_BSTR
  #
  #print "<<--- CameraCommand    ",Cmd,Params  

  if Cmd=="EjectorLine":
    line=int(Params)
    if rs232queue.has_key(line):
      rs232cmd=rs232queue[line]
      ExecuteCmd(rs232cmd[0],rs232cmd[1])
      del rs232queue[line]