I purchased a BASE-3 system at York this weekend. Forum sponsor, Mr. Muffin's Trains, had a great deal that I couldn't pass up. I took the BASE-3 home, connected it and experimented with conventional operation using the BASE-3 system with the CAB-3 app.
Technically, the CAB-3 app exhibits the potential to control both my ZW-L and Legacy Powermaster. I programmed both the ZW-L and Legacy Powermaster with ENG numbers on the BASE-3 just like I had done previously for the BASE-2 . They are set up in CAB mode. I have been able to vary the voltage, control each ZW-L output and Legacy Powermaster. Operation works perfectly using the CAB-1L, CAB-2 and MTC DCS app. That is the good news. However, the implementation on the CAB-3 app is a work in progress. What I observed is as follows:
1. CAB mode wrongly includes momentum. This is disruptive to operation. CAB mode should have no momentum when the momentum is set as "low". This is the Legacy specifcation and aligns with how it is implemented on the CAB-1L, CAB-2 and MTH DCS app for good reason. It is almost impossible to run a conventional locomotive using the CAB-3 app as the voltage slowly "ratchets" up and down at a glacial pace. To use the CAB-3 app with a postwar or other conventional locomotive would require the same instant and responsive throttle control that occurs on the CAB-1L, CAB-2, etc. For example, to operate a postwar engine, a quick jolt is needed to engage an E-unit or get an engine moving. Conversely, this is often followed by rapid backing off of the voltage to maintain control. Toy trains need responsive control. Their physical characteristics have very different control requirements than a Legacy engine. Users must be given the option to have momentum removed by setting to "Low". Medium and high settings can still provide momentum to conventional operators of other engine types with can motors and/or cruise control if desired.
2. The throttle slider shows 200 steps from bottom to top. But CAB mode only has 32 steps. As you slide the voltage up, things get really weird. The voltage increases from step 0 to step 31, drops back to zero at step 32 and increases again up until about step 61 where it drops back to zero and increases again. This pattern keeps repeating. If you set the slider to the maximum, the voltage will oscillate from 0 to 18 volts in this repeating loop about 6 times. From a practical standpoint, this means you really can't control a locomotive. Your average postwar locomotive runs between speed steps 5 and 15 on a Powermaster. Therefore, the entire operating range of a conventional locomotive occurs within a slider movement range of about 1/8 of an inch on the CAB-3 app. This is an impossible arrangement for control.
3. In CAB mode, the direction button is should function like the direction control on a transformer, knocking the voltage off and then back on to its previous position. This is what cycles a reversing unit. When you press the direction button in the CAB-3 app, the voltage bounces back, however the throttle position on the slider falls back to zero. This throws the voltage and throttle position out of sync. This means that if you have an engine in neutral and hit the direction button, the engine will start moving forward but as soon as you try to adjust the throttle, it starts at zero, and the voltage immediately drops off as you increase throttle. This throws the reversing unit again.
Interestingly, I observed these same bugs using the iCab app. I reported them but no correction occurred. I speculuate Lionel had abandoned work on iCab some years ago. I did not press the matter at the time because I was grateful for the free iCab app. However, I have paid real money for the BASE-3 system, and expect the CAB-3 app function as promised.
Until then, I think the best workaround for me has been to use the MTH DCS app. I have been able to correctly adjust voltages for conventional operation through the BASE-3. I have also successfully testing running Legacy, TMCC and Lionchief engines through the MTH DCS app in connection with the BASE-3.
