HP 83751A User Manual page 225

311
Indicates that the command "SHSS" was detected while the
instrument was using the HP 8350 compatible language. These
commands are accepted but no action is taken because the
instrument does not have this feature.
312 -178, "Expression data not allowed;SX: No External Sweep
Indicates that the command "SX" was detected white the
instrument was using the HP 8350 compatible language. These
commands are accepted but no action is taken because the
instrument does not have this feature.
Error Messages
16-27