Time Frame

Problem

Reason for problem

Resolution

Nov92-Apr94

Frequent hangups where all serial communications stop and unit hangs

Non-terminating conditions on loop in original macros

New macros that are guaranteeed to terminate

Nov92-May93

4th rotary mirror not datuming to zero but rather to some random value

Miss wire error on controller card

Fixed miss wire during Aug94 shutdown

Jan93-May94

Non-specific communications hangups where the controller had to be reset

Some could have been mouse software checking serial ports

not fully resolved- not seen lately

Nov92-Present

Dropped phases on the linear encoders

Analog components age causing comparators to fail

None yet

Aug95-May96

4th rotary mirror not datuming to zero but to some value (normally 65535)

Now appears to be some oscillation caused when the encoder is just on the edge of its detection window.

rare occurrence that might be able to be cured by a change in the breakout box

Oct94-Present

Apparent inability of the antenna computer to download macros to the SMC

maybe serial comm parameters or handshaking?

None yet - last couple times it did work

Dec94-Present

Occational loss of communications with the antenna computer

software glitches, or comm handshaking problem

none yet