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Azur Electronics

OPERATING HP 8175A
DIGITAL SIGNAL GENERATOR
The HP 8175A Digital Signal Generator can provide programmable data patterns of: 24 parallel channels, or 2 serial channels; and 2 independent analog arbitrary waveform outputs. It can interact with the device under test using triggers and flags. It can be used with the similar to operate HP 1630D Logic Analyser
 
This HP 8175A Digital Signal Generator was manufactured circa 1989 and by today’s standards is probably totally obsolete, even though it cost almost $27K! For my purposes it is an excellent TTL/CMOS/ECL digital generator, with the added Option 001 Fine Timing and Option 002 Arbitrary Waveform Generator, even if it is some 30+ years old. 
 
Front Panel showing push-button controls
April 2022

The downloaded Operating and Programming Manual of May 1985 (includes Option 001) and the Option 002 Operating and Programming Manual of May 1986 are very comprehensive. Reading through these Manuals and taking new photos where necessary will give me a lot more expertise. The 8175A is a complex and versatile beast, so these are my working notes. 
 
[With acknowledgement and thanks to HP for reproducing some text from their Manuals] 

POWER ON
Power On - the cooling fans start and the 4 Green LEDs next to the Front Panel BNC connectors illuminate. An automatic self-test routine is performed, either standard or extended depending on Rear Panel switch setting. If any failure is detected an appropriate error message will be displayed. On completion of the tests the System Page [Configuration] is displayed.

RECALL STANDARD SETTINGS
Recall Standard Settings - to start with a set of known parameter values and operating conditions.
 
Press SYSTEM key, then NEXT until [Storage] internal menu is displayed.
 
Press CURSOR key to position the cursor in the storage function field.

Press NEXT key until [recall] Standard Settings is displayed.

Press EXEC key to activate.

NOTE: all data is set to 0. 


SETTING UP DATA PATTERNS
Setting Up Data Patterns – for up to 24 Pod Channels (for Parallel), or 2 Pod Channels (for Serial).
 
Press DATA key, then NEXT until Data [Pattern] Setup menu is displayed.

Press ROLL down key to Address 0001.

Press CURSOR down key to move to Address 0001 field.

Press CURSOR right key to move to Channel 0 of Pod 0, at extreme right hand side of display.

NOTE: Pod 2 is left column, Pod 1 is middle column, Pod 0 is right column. Each has 8 channels: 7 to 0 displayed in BINary format. OCTal, DECimal or Denary and HEXadecimal formats are also available.

Press 1 key to set a logic 1 output, the display will auto-roll to Address 0002 field.

Press CURSOR right key to move to Channel 0 of Pod 0.

Press 0 key to set a logic 0 output, the display will auto-roll to Address 0002 field.

NOTE: 0 is the default setting, but will not auto-roll unless set.

Press ROLL up key (if 0 not set) to Address 0003 and CURSOR right key to move to Channel 0 of Pod 0.

Press 1 key to set a logic 1 output, the display will auto-roll to Address 0004 field.

Similarly using ROLL up key to next Address and CURSOR right key to move to Channel 0 of Pod 0.

Set the remaining addresses to program the 8 bits of Channel 0 Pod 0 to 01010101 for addresses 0000 to 0007.

NOTE: the top right of the display shows D and U. 
D indicates that the Pod outputs are currently Disabled. 
U indicates that an Update is required. 


OUTPUT DATA PATTERNS
To output a data pattern, certain preconditions have to be met.

Connect the Pod 0, Channel 0 output to an Oscilloscope using the HP 15408A Plug-On Grabber and Ground Lead. Set volts to 1V/div and timebase to 1µs. This will display the square wave pattern set up.

Press CNTRL key, then CURSOR down to Mode [Single Cycle], then NEXT to change Mode to [Auto Cycle].

Press PRGM key, then CURSOR down then right to change end address to 0007.

Press OUTPUT key, then NEXT to change Output Pods to [enabled].
NOTE: removes the D at top right being displayed.

Press (blue) SHIFT key and EXEC to update.
NOTE: removes the U at top right being displayed.

Press START key and the output is turned on.

... more to follow ...