Operator's guide
The DCM receives streams, but gaps appear in the data some minutes after
Check that the baud rate between the digitizer and the DCM is sufficient for all the data streams you want to transmit. If it is not, the digitizer's output buffer will gradually fill up until no more data can be stored. Increase the baud rate of the digitizer through the DCM (or using Scream!), then set the baud rate of the DCM's input port to the same value.
If you are using triggered output streams, be especially careful to allow a high enough baud rate to transmit data from all possible output streams simultaneously, or you will observe gaps when an event triggers the digitizer.
The DCM receives streams, but
After a reboot, the DCM takes around 2 minutes to begin transmitting. The DCM runs a guardian process which monitors the health of the system. In some circumstances guardian will need to reboot the DCM to attempt to resolve a problem. If the reboot does not help, the DCM will soon find itself in the same position, and guardian will reboot it again.
You can check the time since the last reboot with the command uptime, which will respond with a line like
14:30:32 up 34 min, load average: 1.24, 1.32, 1.10
In this example, the DCM last rebooted 34 minutes ago.
The most common circumstance where guardian will reboot a DCM is when the operator has instructed it to record data, but it cannot do so, either because
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the Flash memory is full, and all connected USB disks are also full,
the Flash memory is full, and no USB disk is present; or
the Flash memory is full, and a USB disk is inaccessible for some other reason (e.g. it is unformatted, incorrectly partitioned, or faulty).
December 2005 | 39 |
