Experimental Physics and
Industrial Control System

[email protected] (Bill McDowell) · Tue, 24 Jun 1997 15:39:53 -0500

 A problem which caused some communication errors between the APS EPICS
 control system and devices controlled by BITBUS, including the Storage
 Ring power supplies, has been solved and repaired.  By designing and
 building a hardware BITBUS analyzer, Ned Arnold identified three
 different types of problems and established that they were all caused
 by the PEP VME BITBUS interface board. The two most troublesome
 problems (those which caused the communications to hang) were fixed
 two months ago by modifying the EPICS drivers to work around the PEP
 problems. The third type of error, which was not fatal but would cause
 nuisance alarms, has now been repaired. This repair required obtaining
 the source code for the VME module from PEP and then debugging this
 code. The Code was obtained via a non-disclosure agreement with PEP.
 The code was written in PLM with German comments (Marion White, an APS
 Physicist, translated). The problem area in the code was identified,
 and the prom was then hand patched.  All PEP boards in the PAR,
 Booster and Storage Ring have been upgraded approx. 25 boards * 2
 links/board = 50 links.  No errors attributable to the  PEP VME BITBUS
 interface board have occurred since the repair was completed.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System