The Field System (FS) uses new antenna control software which works differently to the old version. The FS now manages all conversion of Ra, Dec coordinates to Az, El, including pointing and refraction corrections before sending the commands to the controller. This means that the System Monitor and HMI displays will show pointing and refraction corrections disabled (because they've already been applied). Otherwise, from the operations perspective, the antenna control interface is very similar to before. There are a few things to watch out for though:

1. Sometimes the connection between the FS and the antenna controller can be lost. If this happens the alarm will sound, and you'll see messages like this:

   2012.297.03:58:54.01?ERROR st -998 reading SystemClock1
   2012.297.03:58:54.01?ERROR st -999 TCP/IP connection was closed by remote peer
   2012.297.03:58:54.01?ERROR st   -5 Error return from antenna, see Mbus error.

   and you'll need to re-establish the connection by typing:

   antenna=open (this re-opens the connection)
   antenna=status (if the connection has re-established, you will see several lines of status messages)

2. On windy days we have seen error messages reporting the pointing is outside the tolerance level set in the FS. This seems to be the antenna controller reacting to wind gusts and seems to affect azimuth only. Not much can be done about this. The ptol command can be used to adjust the tolerance to a higher level but in general it's probably better to just put up with it.
3. Wind stows. The antenna should automatically recover from wind stows without intervention
4. Starting up. If the antenna has been used under one of the following conditions, it will not begin to move until the command antenna=operate has been given:
   1. Used under HMI (e.g. a SpaceX track, maintenance),
   2. Has been used in local mode (from the hand-box),
   3. Has been driven manually out of hard limit
   4. Drive not enabled (e.g. is an Emergency stop has been triggered and released)
   5. Drives have been in a Run Not Permitted state (drive or brake problems)
   6. Power switch is on but drives not energised