MOON

Legacy TCS only allows remote telescope communication and control through a serial port on the main TCS computer. In order to allow network communication and control of the telescope we have built software called Telcom to convert tcp/ip sockets to serial communication. To make sure this software is up and running on the BOK telescope you can check the website http://bok.as.arizona.edu:42080 and look for the table marked telemetry. This webpage queries the telcom server about once a second.

You can find a list of legacy TCS commands here .

The Telcom server makes 14 pieces of information available.

To retrieve these values simply open a TCP socket to the Telcom server and send a request. The syntax is as follows.

For Example:

The telcom server will return:

For Example:

As you can see the RA units are not seperated by colons.

If you want to get multiple pieces of data from the telcom server rapidly you can use the ALL keyword. This will return a string containing all the telemetry data described above which will have to be parsed. The string gives values seperated by 1 or more white spaces. The table below shows the order the values are placed in the string.

An example string:

It should be noted that all strings returned on the Telcom socket will end with a carriage return (\r).

The syntax for sending commands to the Telcom server is very similar to sending requests. The syntax looks like:

For Example

This example sets the Right Ascension bias rate at 12.5 seconds per second.

Each command will return:

For Example

The <ERROR_STATE> value will be either “OK” or “BAD”. “OK” means the command was understood and “BAD” means the command was NOT understood (not found in the list of commands). “OK” does NOT mean the command was executed. For example, if the Right Ascension drive is turned off or disable and you send the command:

Telcom server will return :

But the telescope will not start tracking because it can't when the drives are off.

***For brevity sake the complete list of TCS commands will not be written here. Instead they can be found list of network commands

Below are some sample scripts to communicate with Telcom server

This program gets the telemetry from The Telcom server and stores it in a python dictionary object and prints it out in a clean format.

#!/usr/bin/python

""" 
Author: Scott Swindell, Steward Observatory

A short example script to grab telemetry from the BOK Telcom server
the Telcom server and store that information in a python
dictionary object"""

IPADDR = ""     #Available upon request
PORT  = ""      #Available upon request

TELID = "BOK"
REF_NUM = 123
REQUEST = "ALL"

keyList = [
        "ID"            ,
        "SYS"           ,
        "REF_NUM"       ,
        "MOT"           ,
        "RA"            ,
        "DEC"           ,
        "HA"            ,
        "ST"            ,
        "EL"            ,
        "AZ"            ,
        "SECZ"          ,
        "EQ"            ,
        "JD"            ,
        "WOBBLE"        ,
        "DOME"          ,
        "UT"            ,
        "IIS"


                ]

import socket

#instantiate the socket class
telSock = socket.socket( socket.AF_INET, socket.SOCK_STREAM )
telSock.settimeout( 0.5 )

#IPADDR = telSock.gethostbyname(HOST)
telSock.connect( ( IPADDR, PORT ) )#open the socket

reqString = "%s TCS %i REQUEST %s" %( TELID, REF_NUM, REQUEST )


telSock.send( reqString ) #send the request

resp = ""
test = True

#Grab 100 bytes at a time
#from the socket and check for
#timeouts. 
while test:
        try:
                inStuff = telSock.recv( 100 )

        except socket.timeout:
                if resp:
                        print "No Telem Recieved"
                test = False
                break

        if inStuff:
                resp+=inStuff

        else:
                test=False

#turn string into list, seperate by whitespace
resp = resp.split(' ')

cleanResp = []

#remove all empty elements and new line
#and put everything else in cleanResp
for char in resp:
        if char != '' and not char.endswith("\n"):
                cleanResp.append( char )


#gather the telemetry into a dictionary
#for easy referencing           
telemDict = {}
II = 0
for key in keyList:
        telemDict[key] = cleanResp[II]
        II+=1

#print them all out in 
#a nice clean way
for (key, value) in telemDict.iteritems():
        print "|%s\t|\t%s|" %( key.ljust( 10 ), value.ljust( 12 ) )