Invalid Characters - HP 8901B Operation And Calibration Manual

Operation Model
8901B
Measurement Codes
All front-panel keys except the LOCAL key have corresponding instrument-
dependent program codes. These codes consist of either two alphabetic characters, or an alphabetic
character and a number; e.g., M3. The underlined letters on the front-panel key labels are both
letters or the initial letter of the programming code for that function. For example, the code for
-
AUTOMATIC OPERATION is AU, and the codes for TRACK MODE are K1 and KO. The entire
list of programming codes required to make measurements withthe HP 8901B (not including special
functions) are contained in Tables 3-11 and 3-12.
Turning
Off
Functions
When operating in local operation, many of the functions toggle on and off
with successive keystrokes. In remote operation,
a
specific code turns off the functions. The HP-IB
Codes for turning off these functions are given in Table 3-1, "Turning
O f f
hnctions".
lbble 3-1. lhming
Off finctions
Functions Off
Audio Input Off (Mod. Output On)
Calibrate Off
Disable Error Function
Off
Range Hold Off (Auto Range On)
All HP Filters Off
Track Mode Off (Lock Mode On)
All LP Filters Off
dB Ext. Attenuator Off
Pre-display and De-emphasis Off
Ratio Off
-
Code
A0
co
B O
GO
HO
KO
L O
N O
P O
R O
Invalid Characters
The following Table 3-2, "Response to Unused ASCII Characters" lists the Modulation Analyzer's
response to various ASCII characters not used in its code set. The characters in the left-hand column
are ignored unless they appear between two characters of a program code (e.g. M 3, space between the
characters of a function code); in which case, they generate Error 24. The characters in the right-hand
columns, if received by the Modulation Analyzer, will always cause Error 24 (invalid HP-IB code) and
a Service Request message to be generated.
3-14