Troubleshooting DCM installations

This guide applies to DCMs running their native firmware. Guralp Systems Ltd recommend that all DCMs are upgraded to run Platinum firmware – please see this page for more details. This guide does not apply to DCMs that have been upgraded.

I cannot connect to the DCM’s DATA OUT port using a terminal program.

Press ENTER a few times to initiate communication.

If the DATA OUT port gives a login prompt, you should log in with your username and password. If you have not been given a different username and password, try logging in as root with the password rootme. You should change this password as soon as you can with the command passwd

If the DATA OUT port gives an ok prompt, the DCM is running the gcf_out service on that port and has provided you with a FORTH compatibility interface. Type

GETTY

and press ENTER to gain access to the login prompt.

If the DATA OUT port does not respond when you press ENTER, or produces garbage, check that your terminal program is using the same baud rate as the DCM. By default, the DCM uses a baud rate of 115200, with 8 data bits, no parity bit and 1 stop bit, and no flow control.

If the DATA OUT port is not responding at all, check the power supply to the DCM.

I cannot see the DCM’s Web site over HTTP or HTTPS.

There is a problem with the network setup. Connect to the DCM’s DATA OUT port using a terminal program and change the network settings to suit your network. In particular:

  • If the DCM has a static IP address, use ifconfig to verify that the DCM is using the correct IP address. If it is not, change it with
    gcfgdbset net.eth.0 static
    gcfgdbset net.eth.0.netmask 255.255.255.0
    gcfgdbset net.eth.0.address 192.168.0.2

    (replacing 192.168.0.2 with the IP address you want the DCM to use.)

  • If the DCM is using DHCP, use ifconfig to verify that the DCM is using the IP address you expected. If it is not, change the settings of your DHCP server or connect to the correct IP address for the DCM
  • Check that your local PC can route to the DCM’s IP address. For example, if you are using a cross-over Ethernet cable, the two hosts must share a subnet.
  • Check that the DCM’s HTTP(S) server is enabled by issuing one of
    gcfgdbset net.remoteaccess.allow.http yes
    gcfgdbset net.remoteaccess.allow.https yes

    as necessary.

I cannot connect to the DCM’s Scream! server.

Make sure you are using UDP to connect to the DCM. Scream! servers between computers (including the DCM) always use UDP. The Add TCP server… option in Scream! is intended for hardware serial-to-IP converters only.

I cannot GCFPING the DCM’s Scream! server.

  • Check the Receive UDP data checkbox in Scream!’s Network Control window.
  • Open the DCM’s Web site, and check that the option datatransfer.scream.server is set to on, and that datatransfer.scream.server.port is the port you expected.

How can I check the DCM’s Scream! server is running?

Look for the screamserver line in the Tools → Process Overview web page or connect to the DCM’s command line and issue this command

ps | grep screamserver | grep -v grep

You will normally see output such as

2345 root 1972 S /usr/bin/screamserver -r -p 12345 -s 0 -s 1 -s 2 -s 3

To understand these options, issue the command

screamserver -?

Check the the options match your configuration and reconfigure the Scream! server if not. If you get no output, the server is not running and should be re-started in the normal way.

I can GCFPING the DCM’s Scream! server, but no data appears.

Check the DCM is receiving data by selecting Actions → Data Viewer on its Web site. This is a Java applet which provides some of the functionality of Scream!, allowing you to check that data are being received correctly.

DCM-data-viewer

The streams being received at the DCM are listed in the bottom section of the applet. Click on a checkbox to add that stream to the main viewer window.

If you do not want to use the DCM’s Web site, you can find out the number of GCF blocks the DCM has received with the command gnblocks. Each serial port will be listed, with its name, number, key number and device name (as for serialmap) but including the number of blocks received on that port:

Key 0x007005: Blocks 3287 (Port 5, name Port A (COM6),
  device /dev/ttyS2, baud 9600)

The DCM is not receiving any data streams.

  • Check the connection between the digitiser and the DCM by trying to log in to the digitiser’s console. Press ENTER a few times to initiate communication.
  • If the digitiser gives an ok prompt when you press ENTER, check that you have configured the digitiser to output real time data streams. Streams will not appear until a whole GCF block (1024 bytes) is ready for transmission, so a 5 sps stream may not appear until the digitiser has been working for 4 minutes. In addition, you can configure a digitiser to output only triggered streams, in which case it will not appear until a trigger occurs. (There is an exception to this: if you have put the digitiser in the FILING or DUAL filing mode, it will send heartbeat messages to Scream! clients every so often. The DCM will not show these messages in the Data Viewer.)
  • If the digitiser does not respond when you press ENTER, or produces garbage, check that the DCM is using the same baud rate as the digitiser. By default, digitisers use a baud rate of 9600, with 8 data bits, no parity bit and 1 stop bit, and no flow control. To change the DCM’s settings, exit the terminal program, and either
  • use the Serial port configuration → port name Web page, or
  • issue configuration commands such as
    serial.5.service gcf_in
    serial.5.baudrate 9600
    serial.5.handshaking none
    To obtain the port number (here 5) corresponding to a named port, issue the command serialmap.

  • If the digitiser is not responding at all, check the power supply to the digitiser and the cable between it and the DCM.

The DCM is receiving streams, but they do not contain any data.

If the data you see is zero:

  • Increase the Y axis scale using the vertical-scale-icon icon in Scream!’s Waveview window or the corresponding icon in the DCM’s Data Viewer.
  • Check the mass position outputs to see if the masses are locked. A properly unlocked and centred mass should show a mass position within 1000 counts of zero; a locked mass will give a value in the region of 32,000 or −32,000 counts. If your sensor has remote mass locking, you can unlock the masses by navigating to Actions → Digitiser setup and clicking Unlock sensor.

    Locking or unlocking the sensor mass typically takes several minutes to complete.

  • Check the connection between the sensor and digitiser and try again.

If you cannot see the data in the stream, remove any constant offsets by clicking on the Zero streams icon zero-streams-icon in Scream!’s Waveview window or the DCM’s Data Viewer.

The DCM receives streams, but gaps appear in the data some minutes after boot-up.

Check that the baud rate between the digitiser and the DCM is sufficient for all the data streams you want to transmit. If it is not, the digitiser’s output buffer will gradually fill up until no more data can be stored. Increase the baud rate of the digitiser 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 digitiser.

The DCM is not writing to disk.

The DCM normally only writes to disk when one of it’s internal flash memories reach 75% capacity, although you can force a write by selecting Flush Flash from the Tools → Disk Tools web page or, from the console, issuing the command

diskman -f

You can see the contents of the disk from the Tools → Disk Files web page or with the console command

gfat32 ls

Similarly, you can see the contents of the flash memory from the Tools → Flash Files web page or with the console command

ls /nand[01]

If the flash memory is more than 75% full but there is no data on the disk drive, check the RecordFrom and RescordAs settings from the Configuration → Disk web page or with the console commands

gcfgdbget disk.recordfrom.serial.{n}

and

gcfgdbget disk.recordas.{prot}

where {n} is a serial port number and {prot} is one of gcf, miniseed, seed, sac or ascii.

  • If the disk is full and the usagemode is set to UseOnce, it will not be written to.

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