User`s manual

X5-GSPS XMC Module
shut down if necessary because thermal overload may be coming. Better to shut down than crash in most cases. The
temperature failure alert tells the system that the module actually shut itself down. This usually requires that the module be
restarted when conditions permit.
The data acquisition alerts, including over ranges, overflows and triggering, tell the system that important events occurred in
the data acquisition process. Overflow is particularly bad – data was lost and the system should try to alleviate the system by
unclogging the data pipe, or just start over. If you get an overrange alert, then the data may just be bad for a while but
acquisition can continue. Modules with programmable input ranges can use this to trigger software range changes.
Software alerts are used to tag the data. Any message can be made into an alert packet so that the data stream logged includes
system information that is time-correlated to the data.
Table 15. Alert Types
Alert Purpose
Timestamp rollover The 32-bit timestamp counter rolled over. This can be used to extend the
timestamp counter in software.
Software Alert The host software can create alerts to tag the data stream.
ADC Queue Overflow The ADC data queue overflowed indicating the the host did not consume
the data quickly enough.
ADC Trigger The ADC trigger went active.
ADC Overrange An ADC channel was overranged
Alert Packet Format
Alert data packets have a fixed format in the system The Peripheral Device Number (PDN) is programmable in the software
and is included in the packet header, thus identifying the alert data packets in the data stream. The packet shows the
timestamp in system time, what alerts were signaled and a status word for each alert.
Dword # Description
0 Header 1: PDN & Total #, N, of Dwords in packet ( e.g. Headers + data payload )
1 Header 2: 0x00000000
2 Alerts Signaled
3 Timestamp
4 0
5 Software Word
10..6 0
12 X"1303000" & "000" & mq_overflow(0);
35..13 unused
Table 16. Alert Packet Format
X5-GSPS User's Manual 86