20191114

Diving into azcam focus routine and communicating with galil server

• to communicate with the remote instrument server, we must open and close the socket each time.

CLASS InstrumentServerInterface

Open

• creates a socket with a timeout of 60 seconds
• host =
• port =

Close

• closes the socket

Command

• opens the socket
• sends ENCODED string “UTF-8”
  • sends the command and terminator
  • terminator = “\r\n”
• gets reply and checks reply[0] if it equals “OK”
  • if so, decodes the reply and runs through function recv with parameters (-1, “\n”)
• closes socket
• returns reply

Command1

• dont know if this is used

Send

• sends the command and the terminator

Recv

• receives a reply from the socket
• terminates the socket when length bytes are received or terminator is received
• terminator = “\n”
• passes a -1 to length to read through the terminator
• passes a -2 to length to read 1024 bytes
• passes a length parameter to read that amount of bytes
• must DECODE what received
• if length is -1 (or end on terminator)
  • reads in chunks 1 byte at a time and decodes that byte
  • checks to see if byte is “” (empty)
    • if so adds to a loop variable and if that loop variable gets bigger than 10, issues error and returns
    • guess it does this is the terminator never arrives
  • builds the message
  • resets loop to 0
  • checks to see if the chunk is the terminator and if so stop, if not continue looping
• returns the msg chopping off the CR/LF

CLASS PrimeFocusInstrument

• port = 9874
• host = 10.30.1.2 which is bart
• locked = needed to lock communications with galilserver
• uses bokpop
• creates an Iserver with that host and port so use that to talk to galil server with a timeout of 20.

command

• turns lock to true
  • if lock is already true, sleep for 0.01
• sends command with no terminator since it is automatically applied
• receives with length (-2) so reads 1024 bytes
• sets reply to reply[1] so passes over reply[0]
• sends command “CLIENTDONE” with no terminator
• receives that command with length -2 so reads 1024 bytes
  • ignores it
• closes the socket
• REPLIES
  • valid replies starts with “OK: “ and errors start with “?: “
• if reply startswith “OK: “
  • slices reply from [4:]
  • removes the lock
  • closes the iserver
  • returns reply
• if not
  • removes the lock
  • closes the iserver
  • returns reply

SKIPPING FILTERS FOR NOW

get_focus

• calls get_focus_all and returns a single LVDT focus position

get_focus_all

• return string is formatted as “LVDT_ALVDT_BLVDT_C”
  • “01.12301.12301.123”
• sends command “SHOWALLLVDTVALS” to get current LVDT values
• uses command function and cmd string
• I believe it will fully return “OK: LVDT_ALVDT_BLVDT_C”

step_focus

• moves all 3 actuators for instrument focus by specified amount all relative stepper motor steps
• one focus actuator step is 2.645 microns which is -0.0005 LVDT unites. So conversion is -1322.5 um/LVDT unit
• command is ALLFOCUS XXX where XXX is the integer amount to relative move stepper motor
• uses command function above
• then grabs all lvdt values and calculates the mean
• if the delta of the initial mean and current mean is less than 2 then break and everything is happy

get_mean_focus

• grabs LVDT values A, B, C and calculates the mean for them

set_focus

• reported as wrong

set_focus_all

• moves each of the 3 actuators for instrument focus by a specified amount in relative stepper motor steps
• command is FOCUS XXX YYY ZZZ where
  • XXX is actuator A
  • YYY is actuator B
  • ZZZ is actuator C
• dont know what it returns, I assume “OK: “ + something

CSS email Hi Alex,

Here is what I have pieced together so far for your focus scripts.

All communication must go through galilserver which runs on Bart Host IP: 10.30.1.2 Port: 9874

Successful commands return “OK: “ + message Errors return “?: “ + message

Send ends in “\r\n” Received end in “\n”

To send a command, follow the procedure:

1. Open socket
   • Receive reply
     • each reply ends with “\n”
2. Send command
   • each command must end with “\r\n”
3. Receive reply
4. Send command “CLIENTDONE”
   • Must shutdown socket like this
5. Receive reply
6. Close socket

One focus actuator step is 2.645 microns which is -0.0005 LVDT units Conversion: -1322.5 microns per LVDT unit