Warmup Time Operating Notes; Hp 10740A Coupler Based Systems - Manual Monitoring; Systems With Hp10745A Or Hp10746A Cards - Automatic Monitoring; Hp10740A Coupler - Error Signal Information - HP 5501B Operating And Service Manual

3-12. Warmup Time Operating Notes

•
Allow a full 10 minute warmup period for the HP5501B.
•
Warmup completion is indicated by the READY LED on the HP5501B rear panel.
• If warmup is not complete after 10 minutes, a failure may be indicated.
•
If the READY indication at the laser head is not convenient to use because of the mounting
scheme, try the alternate monitoring suggestions that follow.

3-13. HP 10740A Coupler Based Systems - Manual Monitoring

• The REFerence and MEASurement signals terminate at either the HP10760A Counter Card
or the HP10764A/B/C Fast Pulse Converter Card.
•
Each of these cards includes an LED to monitor the presence of the REFerence and
MEASurement signals.
•
The REFERENCE LED will be extinguished until the HP5501B is ready for use.
HOWEVER, FOR SYSTEMS WITH MULTIPLE HP 10760A CARDS
•
Every ODD HP10760A that uses the replicated REF and -REF will have their REFERENCE
LED lit during the laser head warmup period. (This is due to inversion in the replication
circuitry.) Note that this does not apply to multiple HP10764A/B/C card installations.
•
The MEASUREMENT LED will momentarily light several times during the laser head warmup
period provided that the HP10780A Receiver is aligned properly with the beam. (This occurs
because the laser periodically produces functional optical frequencies during warmup.)
The above monitoring scheme assumes no reversal of the REF and -REF lines in the cabling.

3-14. Systems with HP10745A or HP10746A Cards - Automatic Monitoring

3-15. Systems with these cards can use the system computer and software to monitor the laser head
warmup. Before describing the software, it will be helpful to examine some background
information on the HP10740A Coupler, HP10745A HP-IB Interface, and HP10746A Binary
Interface.

3-16. HP10740A Coupler - Error Signal Information

•
Four error signal lines are provided on the HP 10740A Backplane:
- REFERENCE ERROR BIT
- MEASUREMENT ERROR BIT
- V.O.L. ERROR BIT
- OVFL BIT
3-14
NOTE
HP5501B
Operation