The checkboxes in the Buffer Writing column control data recording in the five different GSM networks supported by the instrument.
If buffer writing is enabled for a particular GSM network (box checked), the GSM layer 3 uplink and downlink messages transferred during a GSM-MS Signalling test session are stored in a ring buffer. The buffer size corresponds to approx. 3200 messages. Message types that are connected with information displayed in the CMU measurement menus, e.g. the MS receiver reports, are not recorded. Recording is continued even after a handover or a change of the network.
The contents of the ring buffer can be written to a binary file any time (even while Buffer Writing is enabled); see Save to File softkey below. Saving the buffer contents clears the buffer. On the other hand the buffer is not cleared when Buffer Writing is enabled.
Remote control:
The commands for the layer 3 message log belong to the GSMxxx-MS Signalling
function groups:
MMEMory:L3Msg:BWRiting ON | OFF