Agilent Technologies E5023U, Upgrade Manual

Page: 12 / 26

12 Chapter 2
Upgrade Procedure
Step 1: Checking the E8491A serial number
E8491A-01
S E R V I C E N O T E
E8491A IEEE-1394 PC Link to VXI, C-Size
E8491-66501 PC Assembly - PC/VXI Interconnect
Serial Numbers: US39000231 and below
Clock and sync signals fail when using VXI backplane ECL trigger
lines.
To Be Performed By: Customer or Agilent Personnel
Parts Required: None
Situation:
In multi-module systems, the clock and sync signals can be distributed between modules
using the ECLTRG lines on the VXI backplane. This works as long as all modules are
designed according to the current VXI specification. Unfortunately, the E8491A circuit
design had clamping diodes on the ECL Trigger lines. These diodes corrupt the ECLTRG
waveform causing commiunication failures between VXI modules.
Solution / Action:
Remove clamping diodes CR401, CR402, CR403 and CR404.
ADMINISTRATIVE INFORMATION
SERVICE NOTE CLASSIFICATION:
MODIFICATION RECOMMENDED
ACTION
CATEGORY:
IMMEDIATELY
ON SPECIFIED FAILURE
AGREEABLE TIME
STANDARDS:
LABOR 0.5 Hours
LOCATION
CATEGORY:
CUSTOMER INSTALLABLE
ON-SITE
SERVICE CENTER
SERVICE RETURN
INVENTORY: SCRAP
SEE TEXT
USED RETURN
PARTS: SCRAP
SEE TEXT
AVAILABILITY: PRODUCT’S SUPPORT LIFE AGILENT RESPONSIBLE UNTIL: November 2003
AUTHOR: DMT ENTITY: 0940 ADDITIONAL INFORMATION:
© 2000 AGILENT TECHNOLOGIES
PRINTED IN U.S.A.
SUPERSEDES: NONE
DATE: November 2000