All DK-DPU door phones are now equipped with the new AKM chip to provide enhanced versatility and options. The major new feature is the ability to change the volume and MIC settings from another digital phone. This feature is available on the G1E and GDS systems.
The method of altering volume is different for G1E and GDS systems.
On the G1E a digital phone while it is talking to the DPU presses SPD PRG 6 and then uses either 2 or 6 to select Speaker or Mic and can then adjust the Volume up or down using the Digital phones volume control.
On the GDS the Digital phone presses PRG and the Volume key and then selects 1 or 2 to select speaker or Mic and then uses its own volume control to adjust the DK-DPU volume.
All DK-DPU units shipping now are the new version.