Re: [foxboro] FD30 ERROR CHECKING

I've been logging traffic using a protocol analyser, and found that CRC is 
generated correctly for each message according to the rules of the modbus 
protocol.
In System Monitor there is a set of diagnostic counters for each port, and 
among them a CHECKSUM ERROR counter.
Yesterday I reset the counters and waited for the next packet of false alarms. 
When they showed up, I found that the CHECKSUM ERROR counter had gone up. This 
means that the processor is checking the CRC, but apparently, it is not 
discarding the data....
Any ideas?
Thanks
Pablo> From: plioi@xxxxxxxxxxx> To: foxboro@xxxxxxxxxxxxx> Subject: [foxboro] 
FD30 ERROR CHECKING> Date: Fri, 19 Sep 2008 22:14:30 +0000> > Hi list,> I have 
inherited a satellite telemetry system with an integrator 30B with "FDG" image 
on each end of the communication, one acting as master (onshore) and the other 
as slave (offshore). The system collects process values and alarms from the 
offshore installation and displays it in the onshore control room.> From time 
to time we get a lot of false alarms/shutdowns in the control room. These 
alarms DO NOT appear in the offshore operator station, so we know for sure that 
they are false.> FD30 configuration is not an easy task, and the manual does 
not help much.> My question is: Is error checking programmable? In case it is, 
where do you select the method (CRC, LRC, etc)?> I couldn't find this 
information in the manual (Device Integrator 15 and Device Integrator 30 user's 
guide).> My guess is that currently there is no error checking and bad data is 
passed to the control blocks thus generating the said alarms.> Thanks> Pablo 
Lioi> TOTAL AUSTRAL S.A.> Tierra del Fuego> Argentina.
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Ingresá ya a MSN en Concierto y disfrutá los recitales en vivo de tus artistas 
favoritos.
http://msninconcert.msn.com/music/archive/es-la/archive.aspx
 
 
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