Distinguishing between Mk2 and Mk3 CMG-DM24 digitisers

The DM24 digitiser is available as a stand-alone unit, integrated into instruments (such as the CMG-5TD) and integrated with acquisition modules (such as the CMG-DM24S3EAM or the older CMG-DM24S3DCM). The DM24 underwent a significant design change in late 2005, when the Mk3 was introduced, but there are still many Mk2 units installed and giving good service. The two versions require different firmware. This page describes how to tell whether you have a Mk2 or a Mk3 DM24 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:

DM24 Mk2 and Mk3

Installations with integrated acquisition units

All digitiser modules integrated with CMG-EAMs, such as the CMG-DM24S6EAM pictured below, are Mk3 units.

DM24S6EAM in cylindrical case

Digitiser modules integrated with CMG-DCMs in black, plastic cases, may be Mk2 or Mk3 units: check the serial number or currently loaded firmware (see below) to tell which version you have.

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) supplied before 2006, or another type of instrument, you may have either type of digitizer: check the serial number or currently loaded firmware (see below) to tell which version you have.

40TD with DM24 module

Checking the serial number:

If the serial number of the digitizer begins with D (e.g. in the sensor T3123/D103,) you have a Mk2 digitizer. Mk3 digitizers have serial numbers beginning with A, B or C (e.g. T3434/AB91.)

Checking the current firmware version:

The DM24 prints its current firmware version to the status stream (the stream with the ID ending 00) when it boots as shown below:

Guralp Systems Ltd - ARM-BOOT v2.0 mgs  08/02/11 (Build 11)
System Code versions loaded :-
Current  0108:0000 Guralp Systems Ltd - DM+FW  v.106  mgs  03/06/11 (Build 55r)
Previous 0110:0000 Guralp Systems Ltd - DM+FW  v.106  mgs  07/02/11 (Build 55a)
Backup   0118:0000 Guralp Systems Ltd - DM+FW  v.106  mgs  03/06/11 (Build 55r)
DSP Code :
0106:0000  dsp1086.bin loaded 2011-07-08  
0107:0000  dsp1086.bin loaded 2011-07-08   Default
Command keys:
C - set real time Clock (2012 1 9 10:51:22 )
I - view/upload InfoBlock
F - run the Forth monitor
S - update System program
O - select Other system program
B - update Boot program
D - update DSP code
T - Toggle default DSP code
Q - Quit maintenance system
0  seconds to auto-start
no key pressed - 
Guralp Systems Ltd - DM+FW  v.106  mgs  03/06/11 (Build 55r)
Running application at 0108:0000 from flash

In the example above, the firmware (current System Code) version is v.106.

For more information, first contact your local distributor or email