HP 8920B Programmer's Manual page 660

Error −171
Error −178
Error −180
Error −181
Error −183
Error −184
Error −200
Error −201
660
Invalid expression
The expression data element was invalid (see IEEE 488.2, 7.7.7.2); for example,
unmatched parentheses or an illegal character.
Expression data not allowed
A legal expression data was encountered but was not allowed by the device at this point in
parsing.
Macro error
This error, as well as errors −181 through −184, are generated when defining a macro or
executing a macro.
Invalid outside macro definition
Indicates that a macro parameter placeholder was encountered outside of a macro
definition.
Invalid inside macro definition
Indicates that the program message unit sequence, sent with a *DDT or *DMC command,
is syntactically invalid (see .
Macro parameter error
Indicates that a command inside the macro definition had the wrong number or type of
parameters.
Execution error
This code indicates only that an Execution Error as defined in IEEE 488.2, 11.5.1.1.5 has
occurred.
Invalid while in local
Indicates that a command is not executable while the device is in local due to a hard local
control (see IEEE 488.2, 5.6.1.5). For example, a device with a rotary switch receives a
message which would change the switches state, but the device is in local so the message
can not be executed.