Often on UKHA_D the question is asked, “What is the difference between an LD11 and an LD10?” well physically they are the same, exactly and the connections to them are also exactly the same so the wiring chart for the 10 is the same as the 11.
- The LD11 supports extended X10 commands, the LD10 does not.
- The LD11 supports soft start/off whereas the LD10 does not.
- The LD11 supports memory dim as does the LD10.
- If you like the LD10 is the dumber, older model.
The extended X10 commands are very useful to those of us using a controller that supports them, like for example HomeVision, as it allows the “X10 device directly to level XX”, this may not seem much but it is a good step. It allows you 63 levels of brightness as opposed to the 16 offered by most other X10 modules meaning you can tailor the light level to suit your taste far better than the older modules.
It also means that you can achieve “scene” lighting using macro and a bit of clever programming with your controller which can be used with very impressive results, particularly in an audio/visual type setup routine.
Soft start basically is what the title suggests, the module, when it receives an “on” command starts from off (0) and returns to the last level at which it was set before being turned off, this is known as memory dim because the module “remembers” the last setting it was at before it relieved the “off” command.
Conversely, soft off is the opposite. When the “off” command is received the module dims back to zero from its current level and switches off.
Over the older LD10 the LD11 is something of a godsend for HA, particularly if you have a bedtime routine and you want the lighting to react differently if everyone is in bed, e.g. not come on at 100%. The reason for this is simple, if you are using the Leviton switches or PIR’s to control the lighting via a controller or a PC then what you do is tell the controller to send this example for working in Homevision, but I am sure it would be similar for HomeSeer etc.:
If Time is dark And “Gone To Bed” Flag is set Then X10 device directly to level 31 End If
What this does is tells the module to switch on and go directly to 50% brightness rather than just going to the previously set level before it was switched off if it is dark and the controller is aware that everyone is in bed.
NOTE: Level 63 causes the module to come on immediately at 100% with no soft start and there is no option known to make the lights extinguish without dimming down. Although in the case of the LD11 setting to level zero is “off”.
So as you can see the LD11 is far more flexible for programming than the older LD10 and, in my opinion, the dimming capability is far smoother than the older module as well.
The one glaring omission from the LD11 and LD10 is status response! Unfortunately very few UK X10 modules have this feature and that is a great shame as it would allow far greater accuracy in dealing with X10. What this means is, should you connect a momentary contact switch to an LD11, when it is operated the module does not send a signal to the controller to make it aware that the module’s status has changed, not even a simple on or off. In my opinion this is one of the biggest failures in almost all the X10 modules available in the UK today.
As I understand it, the newer A10 micro-modules will support status response as well as all the features shown in the LD11, but at a premium! Although to be fair the new modules are an awful lot smaller than the existing units and should make retrofit applications far easier then they currently are. The bad news is it looks as if they will be almost twice the price of the LD11.
All in all the LD11 is a step forward for X10 but not the all singing version that was really wanted, or indeed needed, to allow X10 to really come into its own. However, when compared with the plug-in modules or the older LD10 then it is well worth having the extra features, especially when there is no premium in the price for it!
Additionally as far as anyone is aware all the DIN rail dimmers now available have the newer firmware anyway so even when you buy a supposed LD10 it is in fact an LD11 that you will receive.