This article will help you diagnose problems with a DM24 digitizer, where
a PC with Scream! software installed
a 10 – 24 V DC power supply; and
a Güralp Systems power/data cable. This cable has a blue wire ending in a 9-pin serial connector, and a grey wire ending in red and black bare wires. Both are connected to a 10-pin round connector at the other end.
Identify if you have a DM24 mk2 or a mk3 digitizer.
Installations with separate digitizers: The stand-alone mk3 digitizer module has ports on both sides of the case. The mk2 digitizer has ports on only one side. It is also larger. In the photograph below, the mk3 is on top.
Installations with digital sensors: If you have a 3ESPCD, 3TD or 40TD which is in a single-piece sleeve, you have a mk3 digitizer.
If you have a 3ESPD, 3TD or 40TD with a two-piece sleeve (with a join across the middle marked by screws), or another type of instrument, you may have either type of digitizer.
If the serial number of the digitizer begins with A (e.g. in the sensor T3965/A103,) you have a mk3 digitizer. Mk2 digitizers have serial numbers beginning with D (e.g. T3034/DA91.)
The rest of this how-to is for DM24 mk3 digitizers only. There is a separate troubleshooting guide for mk2 digitizers elsewhere on this Web site.
Power on your PC and run Scream!.
In the main window, select File – Setup... from the menu. Switch to the Com Ports tab.
If this is the first time you have run Scream! on this computer, the Com Ports tab will open automatically.
Find the entry for the serial port on your computer.
If you have more than one serial port, choose one to attach to your digitizer, and find its entry.
Set the Baud Rate to the correct value for your digitizer.
If you have not changed the baud rate of the digitizer, set it to 38400.
If you have configured a different rate, and can remember it, use this rate.
Click OK.
From the main menu, select File – Terminal....
A window will appear asking you to Select Port to open.
Choose the serial port you are going to use from the Port drop-down menu. Leave the Link Type set to Direct Serial.
A Terminal window will open.
If the Data Out port of the digitizer is connected to anything, disconnect it.
Connect the 9-pin serial connector on the data/power cable to your PC's serial port.
Connect the red and black wires to a 10 – 24 V power supply.
Connect the round connector to the digitizer's Data Out port. Watch the Terminal window while you are doing this, and listen.
You should hear a click from inside the digitizer. This is the internal relays resetting.
Soon, boot-up messages should appear from the digitizer. The messages depend on the digitizer model.
The boot-up messages begin
Guralp Systems Ltd - ARM-BOOT v01.0 mgs 06/10/05 [b 022] System Code versions loaded :- 0103:0000 Guralp Systems Ltd - DM+FW v.102 mgs 01/02/06 (Build 58) 0107:0000 Guralp Systems Ltd - DM+FW v.103 mgs 05/09/06 (Build 12) Default 010B:0000 Guralp Systems Ltd - DM+FW v.102 mgs 16/01/06 (Build 55) DSP Code : 0101:0000 DSP flashed 2005-12-13 Default 0102:0000 not loaded Command keys: C - set real time Clock (2006 10 3 13:39:57 ) I - view/upload InfoBlock F - run the Forth monitor R - Run an application E - Erase an application S - update System program B - update Boot program D - update DSP code T - Toggle default DSP code N - set the default application Number (2) Q - Quit maintenance system 5 seconds to auto-start4 3 2 1 0 no key pressed - Running User program
If you do not see boot messages, follow this link.
If you see a different message, follow this link.
If the digitizer is working, Scream! will report Connection closed by remote instrument. Click OK. Streams should soon begin appearing in Scream!'s main window.
If Scream! does not report Connection closed by remote instrument after the boot messages, follow this link
The digitizer should transmit one or two status blocks (ending 00) immediately. When this happens, Scream! will recognize the digitizer and add its icon to the left-hand pane. Data streams may follow later.
The digitizer may be in FILING mode, or configured to output no continuous data.
Choose File – Terminal... and connect to the digitizer terminal. You should see a message like
DM24 DEMO00 CMG-3T Command Mode 19 blocks in buffer | 237 blocks free
Type
0 7 CONTINUOUS DIRECT GO
followed by ENTER.
Data streams should start appearing in Scream!.
The configuration memory may be corrupted.
Choose File – Terminal... and connect to the digitizer terminal.
Power cycle the digitizer. When you see a short boot message, immediately press ESCAPE. You should see the message
************ Operator intervention
and the DM24 will drop to a prompt.
If you do not see this message, or the short boot message, your digitizer may be a mk2 unit. See the separate troubleshooting guide for DM24 mk2 digitizers.
Type
TRASHFRAM REBOOT
The digitizer will reboot with its factory settings.
Keeping the Terminal... window open, you should see the normal boot messages. Scream! will then close the window with a Connection closed by remote instrument message, and data streams will appear.
DM24 mk3 digitizers produce a short message at 38400 baud when they are powered up. The message looks like
I/OPort =$42 : RTModule no I2C ACK @ $78 MPE ARM ANS ROM PowerForth v6.20 ARM Serial BootStrap v1.100, 11 August 2003 Copyright (c) 2002-3 GSL, EDSL & MicroProcessor Engineering Ltd. . Port 0 115200 baud..
The digitizer then switches to the configured baud rate.
If you see this message followed by garbage (data), look for the line beginning Port 0. This line displays the baud rate the digitizer is using: here, 115200 baud. Open the Com Ports window and set the serial port to this baud rate. Start this how-to again.
If you see this message but the digitizer freezes, repeats this message, or does not respond at the displayed baud rate, the configuration memory may be corrupted.
If necessary, open the Com Ports window and set the serial port back to 38400.
Choose File – Terminal... and connect to the digitizer terminal.
Power cycle the digitizer. When you see the short message, immediately press ESCAPE. You should see the message
************ Operator intervention
and the DM24 will drop to a prompt.
Type
TRASHFRAM REBOOT
The digitizer will reboot with its factory settings.
Keeping the Terminal... window open, you should see the normal boot messages. Scream! will then close the window with a Connection closed by remote instrument message, and data streams will appear.
The DM24 may not be powering up.
If a GPS receiver is connected, unplug it and power cycle again. Damaged GPS units or cables can pull the power supply voltage down below the level the digitizer needs to operate.
If the digitizer now works, the problem lies with the GPS receiver or cable.
If the digitizer still does not respond, measure the current drawn when it is switched on.
If the digitizer draws no current, it is not receiving power. If possible, swap the power cable for another and try again.
If the digitizer still draws no current, it may be damaged. Contact Güralp Systems for assistance.
If the digitizer draws some current, and you have access to a working digitizer, replace the digitizer with the working one and connect it to the same power supply. Measure the current drawn.
Compare the amount of current drawn by the working digitizer with the amount drawn by the one you are troubleshooting. If the two currents are significantly different, there is internal damage to the digitizer. Contact Güralp Systems for assistance.
If the current seems normal, the problem may be with the data output port. Two pins on the GPS port provide an emergency terminal connection at 38400 baud.
You will need to make up a special cable to use this interface. The pin assignments are given in the digitizer manual.
The baud rate of the digitizer may not be set correctly.
In Scream!'s main window, click File – Setup.... Switch to the Com Ports tab.
Set the serial port to a different baud rate.
Alternatively, set the port to Auto-Detect. Scream! will try and find the baud rate automatically.
Power cycle the digitizer and look for boot messages as above.
If you still do not see boot messages,
When the digitizer is working, you should reinstall it with your other equipment. Do this in steps, and check that the system still works after every step.
If you disconnected a sensor or sensors, reconnect them.
If you disconnected the GPS receiver, reconnect it.
Using Scream! on your PC, check that the digitizer is outputting streams.
Reconfigure the digitizer according to your requirements.
When the digitizer reboots, check that it outputs data in the way you expect.
Disconnect your PC, and connect the digitizer's DATA OUT port to your normal data collection hardware and power supply.
Set the baud rate of your data collection hardware to the output baud rate of the digitizer. Check that streams are received.
If streams are not received, check the power supply in the installation. Unplug sensors and GPS, and power cycle the digitizer. If this solves the problem, your power supply cannot provide enough power to run the full installation.