Cruise Commander M only goes full speed

My guess is that it's not seeing the serial data. Did you make sure that wire is connected?

@rplst8 posted:

My guess is that it's not seeing the serial data. Did you make sure that wire is connected?

Likely this^^^^^^.

Cruise Ms and wireless tethers battle for serial data. Cruise Ms usually lose. You have to buffer the signal somehow. Some use custom buffer circuits. If your drawbar has a two wire IR, a three wire replacement will help.

Pete

What Pete said ^^^^^^^^^ to test the theory, temporarily unplug the IR drawbar wiring from the motherboard, and see if you gain back control. Then you’ll know that it’s a serial strain issue …..

Pat

@Norton posted:

Cruise Ms and wireless tethers battle for serial data. Cruise Ms usually lose. You have to buffer the signal somehow. Some use custom buffer circuits. If your drawbar has a two wire IR, a three wire replacement will help.

How about this: Improved R2LC/R4LC Serial Data Buffer

I recently installed the CCM into my Lionel 6-28028 Allegheny (TMCC). This engine uses a IR wireless tether.

Identified two wire cable from IR tether and unplugged from motherboard.

Used ohm meter to identify which wire was the serial data - in my case it was an orange wire.

Cut orange wire near CCM location. Used the connector that came with CCM that had two wires preinstalled  to pin 1 and pin 2. Slid heat shrink tubing on both ends of the cut orange wire to insulate solder connections.

Soldered the wire from pin 1 of the CCM connector to the end of the orange wire coming from the motherboard.

Soldered the wire from pin 2 of the CCM connector to the end of the orange wire going to the IR tether.

Slid heatshrink tubing to cover the solder joints, but did not heat - wait until testing done.

Plugged IR tether two wire cable back into mother board.

Tested with cab still off - speed control worked, but no TMCC controlled sounds from tender.

Used scope and found that serial data to CCM Pin 1 was 5 volt pulse, whereas serial data from CCM Pin 2 to IR tether was only 1volt pulse. CCM serial data buffer not powerful enough to drive my IR tether. Had to buy a three wire buffer that went between CCM Pin 2 and IR tether, and required a connection to the +5VDC on the R2LC. Did so, using heat shrink tubing just slipped on.

Test was Okay - so heated shrink tubing, dressed wiring, put engine back together.

All works great!!!

BTW - the three wire buffer had its own heat shrink installed so could not exactly determine what it was, but I am sure it is a transistor and a resistor or two. I was also told that a couple people who had a similar situation were able to make it work using a 33K resistor connected to the serial data output of CCM Pin 2 to +5VDC of the R2LC

Pin 2 on the CCM is supposed to be buffered data but I have never had it work. Great product otherwise.

Pete

@Norton posted:

Pin 2 on the CCM is supposed to be buffered data but I have never had it work. Great product otherwise.

Pete, it depends on the CCM.  The "Odyssey" version has "duty cycle" output on pin-2 of the 10-pin connector.  It's the signal to feed the Railsounds board to control the diesel ramping for RailSounds 4 boards.  The "generic" or "all steam" CCM has serial data repeated on pin-2 of the 10-pin connector.

@gunrunnerjohn posted:

Pete, it depends on the CCM.  The "Odyssey" version has "duty cycle" output on pin-2 of the 10-pin connector.  It's the signal to feed the Railsounds board to control the diesel ramping for RailSounds 4 boards.  The "generic" or "all steam" CCM has serial data repeated on pin-2 of the 10-pin connector.

Don’t the diesel Railsounds 4 boards also need serial data for horn/bell and confirmation honks though?

@rplst8 posted:

Don’t the diesel Railsounds 4 boards also need serial data for horn/bell and confirmation honks though?

Apparently Railsounds boards themselves don’t require a lot of current from serial data. Add in AC regulators and smart smoke units and its gets dicey.

If pin 2 was of any use, add on buffers wouldn’t be needed.

Pete

@Norton posted:

Apparently Railsounds boards themselves don’t require a lot of current from serial data. Add in AC regulators and smart smoke units and its gets dicey.

If pin 2 was of any use, add on buffers wouldn’t be needed.

I’ve definitely used the generic version as GRJ stated, with serial out on pin 2. In my case I used it for two Atlas diesels that had the VCO on the motherboard to drive the diesel engine ramping sounds. So, I know it can work properly.

That said, I’ve seen them act as @MED described where the output is reduced to 1 volt. I don’t know why this happens though. In the case that it happened for me, the board also failed to match speed with an identical board and locomotive.

I sent it back to Scott and he reprogrammed it, then all was well after that.

P.S. I should note, I think this was the case. I know that I observed both behaviors, but I can’t remember for sure if both events were the same CC-M. I’ve taken notice of the thread about keeping a journal, and I’m going to heed this advice. I keep notes at work, but I’ve never done so for a hobby before, and my memory is getting full, so to speak.

@rplst8 posted:

I’ve definitely used the generic version as GRJ stated, with serial out on pin 2. In my case I used it for two Atlas diesels that had the VCO on the motherboard to drive the diesel engine ramping sounds. So, I know it can work properly.

That said, I’ve seen them act as @MED described where the output is reduced to 1 volt. I don’t know why this happens though. In the case that it happened for me, the board also failed to match speed with an identical board and locomotive.

I sent it back to Scott and he reprogrammed it, then all was well after that.

P.S. I should note, I think this was the case. I know that I observed both behaviors, but I can’t remember for sure if both events were the same CC-M. I’ve taken notice of the thread about keeping a journal, and I’m going to heed this advice. I keep notes at work, but I’ve never done so for a hobby before, and my memory is getting full, so to speak.

The reason the output is chopped down when you connect the tether LED is the operating voltage of the tether LED.  You can fix that by sticking a 330 ohm resistor in series with it, it'll still output plenty of IR but not stomp on the serial data line so hard.

@gunrunnerjohn posted:

The reason the output is chopped down when you connect the tether LED is the operating voltage of the tether LED.  You can fix that by sticking a 330 ohm resistor in series with it, it'll still output plenty of IR but not stomp on the serial data line so hard.

That’s a good tip for the wireless tether, but as I said I was using it in a diesel and the output was connected to the RailSounds board. Also, it only happened with one of the CC-M boards I had. So I think something was up with that particular copy I had.

I would expect the RS4 boards to have a high input impedance for the serial data line since it would have been normally connected directly to the R2LC in the older Atlas diesels.

That said, I’ve seen such inconsistent behavior with the Lionel serial data across board versions and revisions, who knows. Either they are failure prone, extremely sensitive, or there is some blackbox knowledge that I just don’t possess.

Yes, there was an update to the CC-M to minimize the issue of a weak serial data signal.  I'm not entirely sure if it was just software or a hardware change as well.

FWIW, Lionel used to have the back-EMF boards that were basically an older version of the CC-M, they all exhibited more sensitivity to the serial data line loading.  When I used those, I almost always had to include a serial port buffer in the mix.

I will try these suggestions.  If I build the "Improved Serial Data Buffer" what do the In and Out wires connect to? That is to say does the In come from the R2CL serial data out on pin 1 and the Out goes to the CCM board pin 1?

@Gary-O posted:

I will try these suggestions.  If I build the "Improved Serial Data Buffer" what do the In and Out wires connect to? That is to say does the In come from the R2CL serial data out on pin 1 and the Out goes to the CCM board pin 1?

Here's the connections:

@Gary-O posted:

I will try these suggestions.  If I build the "Improved Serial Data Buffer" what do the In and Out wires connect to? That is to say does the In come from the R2CL serial data out on pin 1 and the Out goes to the CCM board pin 1?

Why not try the 300 ohm resistor first? K.I.S.S. is my motto.

Pete

Thanks John, Norton and everyone!!  I have what I need now.  I will try the 300 ohm resistor first, but will have to wait until tomorrow.

@MED posted:

I recently installed the CCM into my Lionel 6-28028 Allegheny (TMCC). This engine uses a IR wireless tether.

Identified two wire cable from IR tether and unplugged from motherboard.

Used ohm meter to identify which wire was the serial data - in my case it was an orange wire.

Cut orange wire near CCM location. Used the connector that came with CCM that had two wires preinstalled  to pin 1 and pin 2. Slid heat shrink tubing on both ends of the cut orange wire to insulate solder connections.

Soldered the wire from pin 1 of the CCM connector to the end of the orange wire coming from the motherboard.

Soldered the wire from pin 2 of the CCM connector to the end of the orange wire going to the IR tether.

Slid heatshrink tubing to cover the solder joints, but did not heat - wait until testing done.

Plugged IR tether two wire cable back into mother board.

Tested with cab still off - speed control worked, but no TMCC controlled sounds from tender.

Used scope and found that serial data to CCM Pin 1 was 5 volt pulse, whereas serial data from CCM Pin 2 to IR tether was only 1volt pulse. CCM serial data buffer not powerful enough to drive my IR tether. Had to buy a three wire buffer that went between CCM Pin 2 and IR tether, and required a connection to the +5VDC on the R2LC. Did so, using heat shrink tubing just slipped on.

Test was Okay - so heated shrink tubing, dressed wiring, put engine back together.

All works great!!!

BTW - the three wire buffer had its own heat shrink installed so could not exactly determine what it was, but I am sure it is a transistor and a resistor or two. I was also told that a couple people who had a similar situation were able to make it work using a 33K resistor connected to the serial data output of CCM Pin 2 to +5VDC of the R2LC

I'm a kind of picture guy.  Could you provide a circuit diagram of what you had to do?

I having a hard time picturing this.  Sorry for my confusion.

@DaveGG here a concept schematic. Original wiring shown in upper area, wiring after install in lower area. You may not need a Buffer on the Serial Data. If you do need the buffer, I tried to show where the buffer is inserted. I also included the pin definition of the R2LC, and I believe it is the same for R4LC's (I don't remember exactly where I got this, but I believe it was a post by @gunrunnerjohn, and I believe he stated R2LCs and R4LCs have the same pin definition - my apologies if I am wrong).

Remember that the concept is based on my engine. The main point is that the color of the wire that is the serial data could be different in your engine. I suggest you follow the cable from the IR tether back to the motherboard, unplug this cable from the motherboard, and then use an ohm meter (ohm function of a voltmeter) to go from pin 24 of your radio board to the pins the cable from the IR tether plugs into to make sure which wire is the Serial Data.

@MED posted:

I also included the pin definition of the R2LC, and I believe it is the same for R4LC's (I don't remember exactly where I got this, but I believe it was a post by @gunrunnerjohn, and I believe he stated R2LCs and R4LCs have the same pin definition - my apologies if I am wrong).

You are correct, the R2LC and R4LC have exactly the same pinouts.

You may want to revisit and verify the power wiring to the M. If you are simply swapping the 4 pin power/motor connector from a Lionel DCDR there's a good chance the power wiring may be out of phase. Not sure what engine you have but if I am using the M I verify and re-verify the power phasing. If the power is out of phase, the serial comm connection will get nuked since it referenced to ground/chassis and you will get the behavior you describe. I had this happen at least once and didn't manage to hurt anything. Of course, my initial testing is always done at a reduced voltage. Simple thing to check!

@Norm Charbonneau posted:

You may want to revisit and verify the power wiring to the M. If you are simply swapping the 4 pin power/motor connector from a Lionel DCDR there's a good chance the power wiring may be out of phase. Not sure what engine you have but if I am using the M I verify and re-verify the power phasing. If the power is out of phase, the serial comm connection will get nuked since it referenced to ground/chassis and you will get the behavior you describe. I had this happen at least once and didn't manage to hurt anything. Of course, my initial testing is always done at a reduced voltage. Simple thing to check!

Oddly, I've never seen this issue Norm.  Not saying it can't happen, but the standards for wiring the Lionel DCDR and the Cruise Commander M are identical.  What I have seen in K-Line upgrades is the motor wiring reversed so that the locomotive starts in reverse instead of forward.

Since the DCDR PWM inputs from the R2LC are opto-isolated, I can see where the DCDR would probably run fine with reversed power, so that's an interesting observation.

The "simple" solutions didn't work.  Will have to build a buffer.

I still have a couple of my Improved R2LC/R4LC Serial Data Buffer kits available.

Thanks John but the engine has a lot of spare room. I think I can easily fit it with a scratch built one.  I did have a question though.  The picture of your finished unit shows an MCP6241E IC but the schematic uses an MCP6001T.  I assume they are essentially the same?

They're the same specs, the MCP6241-E/SN I actually use has a larger footprint and is easier to solder.  The schematic is the previous all surface mount design.  Same exact function, but much more difficult for the novice to build.  Since I was offering kits, I figured to make it a bit easier to build.  The other parts are thru-hole, but the thru-hole op-amp made them too large.  When I'm building something to put inside the locomotive, I try to make it as small as possible, you don't always have tons of room.