accessory decoder

[paul_mcginity]

I am back again with my second question to the forum gurus.

I would like to use my decoder Hornby R8247 to run  my 2 aspect signals.

I have searched in all the usual places to find how you make the decoder operate in a continuous mode.

Would someone please guide me through the manouvres to operate these lights.

Thank you in anticipation.

Paul M McGinity

Tasmania

[96RAF]

Its all in here:

https://www.hornby.com/uk-en/downloads/view/download/item/150

 

Essentially you write value 0 to CV515 having completed other steps ahead of this - it on the page spoken to under 'Advanced  Addressing using the Elite Unit' then detailed in 'Programming'.

 

You should also be able to do this in Railmaster although I havent read up on that yet..

[Chrissaf]

It will depend upon what controller you have:

.

If RailMaster. Look at the graphic on page 73 of the current version 1.64 user guide manual. You will notice the 'Always On' check-box to the right hand side. Put a tick in the check-box against the port that will connect to your signals and save the setting to the R8247.

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If Elite. There is a reference in the R8247 Accessory Decoder instructions that the 'Always On' setting can be done by adjusting CVs (RAFs link above shows the detail - see the middle section of the guide under 'Programming'). Personally, I would download the FREE evaluation copy of RailMaster and use that to adjust the setting as in the first paragraph above. Note: Strangely no mention is made in the Elite controller user guide on how to do this, its only on the Accessory Decoder instruction sheet (RAFs link).

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If Select. It is not possible with the Select, as it is very limited in reading & writing CVs. You can't use the RailMaster (in evaluation mode) option with the Select either, as RailMaster is not supported with the Select. Whereas it is supported with the Elite.

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Once you have the R8247 port successfully configured for 'Always On' then just operate the signal exactly the same way as you would operate a point. Call up the appropriate R8247 port number (address) and operate.

.

Note: CV515 is for port 1 of the R8247, CV516 for port 2, CV517 for port 3 and CV518 for port 4

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Value written to the above CVs

0 = 'Always On'

1 = Pulse 0.1 sec (for solenoid point motors) - default setting.

2 to 255 = Pulse 0.2 sec to 25.5 sec (above 0.5 second not recommended for solenoid point motors)

[96RAF]

@Chris

The R8247 'manual' says to set CV515 to value 0 for always on, else 1-255 for 0.1 seconds - 2.55 seconds for pulse.

 

But you also have to previously have fiddled with CV513 in Simple Addressing to set up group addressing - all very un-user-friendly. RM method is much easier.

 

Of course all this has to be done on the programming track, bit of a pest if you already have the thing wired in.

[Chrissaf]

@Chris

The R8247 'manual' says to set CV515 to value 0 for always on, else 1-255 for 0.1 seconds - 2.55 seconds for pulse.

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As I found out when I followed your link. We were both writing and editing at the same time and got out of sync with our posts. However, I feel our joint final text now has enough clarity.

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Rob, point of interest query. In the CV table on your linked instruction sheet it shows the CVs in the 500 range with a /CVn number where n = 1 to 9

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I can't find any reference in the document to the significance of the CV1 to CV9, do you have any ideas?

[96RAF]

@Chris

OK lets run through it as I see it. The R8247 leaflet (manual) gives specific instructions for setting up the R8247 only using either a Select or an Elite. For other controllers they suggest reading their applicable manual obviously.

 

As the Select uses the 61 >> address format then I will talk to the Elite process as this is probably what RM uses in the background disguised by the code.

 

The initial setup is to put the acc decoder into Group Addressing mode by writing to CV513. This allows you to set value 1 which is port 1 on address 1 which the Elite then iterates to allocate 2, 3 and 4 to the first group of ports.

 

The next acc decoder you do you set up is given CV513 value 5 i.e. address 5 and it sets 6, 7 and 8 and so on to those 4 ports of group 2.

 

This process is iterated for as many acc decoders as you have and thus sets groups of 4 ports along the way.

 

Having got this far we are looking at setting the ports for a pulse, the length of which we can also set or if value 0 then it sets continuous output. A pulse being a continuous output of a determined dwell time then switch off.

 

Now what about this CV513/CV1, etc as shown here:

/media/tinymce_upload/c6e4535d764d17f2068f15114c592aee.PNG

 

I have no idea what LSB or MSB stands for...

 

I think the lower CV number (1-9) is the register where Hornby stores the additional information about the higher CV number (513-521) in that when you connect to and write Acc Decoder group 1 address 1 port 1 - i.e CV515 it puts the dwell time value in CV3. CV515 itself holding the value of the port it represents in that group e.g. Point address 1 port 1 left and right.

 

CV516 i.e. port 2 of that group (Point address 2 say)  holds its dwell time value in CV4.

 

In the next Acc Decoder group you connect and read/write to CV513 holds the point addresses 5 to 8 and CV515 holds info about Point address 5 port 1 and so on.

 

Further down the list CVs 7, 8 and 9 hold the information shown but tagged to the group address for recall against that individual Acc Decoder which may not be Hornby, as per any loco decoder.

 

I may ask HCC for their opinion of why that table is so presented in the manual, but thats my interpretation of it - and I am open to rock throwing as usual..

 

[96RAF]

@Chris

I can't find any reference in the document to the significance of the CV1 to CV9, do you have any ideas?

Yes

I've replied but included a screen grab so held Adam's release.

[St1ngr4y]

@RAF

 

LSB and MSB stand for Least Significant Byte and Most Significant Byte respectively. In computer terms, if you are using two bytes to hold a number, the LSB will hold values 0-255,  the MSB will only be non-zero when you need to hold values >255. When two bytes are used together, they are capable of holding a value in the range 0 to  65535.

 

Ray

[96RAF]

@Ray

So we are saying that to hold all the unique recall data in that table for any possible value in the acc decoder range of 1-63 (i.e. Point/Port address of 1-252) is possible by way of bytes value 0-65535. 

 

Apologies to the OP but we appear to have drifted off his topic a little.

[Chrissaf]

Your explanation logic makes sense. I recognise the CV1 as being a fairly standard CV number used by decoders to hold the DCC address.

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Strange that the table shows the default to be 15 for this CV......when the default port addresses for a R8247 taken out of the box is 1, 2, 3 & 4

[Rog RJ]

The use of CVs in accessory decoders is in the PDF from the NMRA on page 9.  See http://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-9.2.2_decoder_cvs_2012.07.pdf 

 

Alternative use of numbers in the 1 and upwards range and 513 and upwards range is due to inabilty of some command stations to program the higher numbers.

[St1ngr4y]

@Ray

So we are saying that to hold all the unique recall data in that table for any possible value in the acc decoder range of 1-63 (i.e. Point/Port address of 1-252) is possible by way of bytes value 0-65535. 

 

Apologies to the OP but we appear to have drifted off his topic a little.

All I am saying is that, in computer terms, two bytes (16 bits) are capable of holding a value in the range 0 - 65535, and that these two bytes are referred to as LSB & MSB. How the logic of the decoder makes use of this information may be different to simply being a decoder address in this range, especially when the manual gives ranges of 1-15 for the LSB and 0-7 for the MSB, rather than the mathematical ranges of 0-255 for each.

Ray

[96RAF]

@rog

that NMRA document explains thing fairly well once you scroll down to the accessory decoder bit, including the dual CV numbering and to some extent (to me anyway) the lsb and msb significance. I thought it may be similar to short and long addresses on loco decoders, but ....

 

cv2 / cv514 is missing from the r8247 manual table as it is not supported by the unit apparently.

 

interesting that acc decoders have the full gambit of cvs including the dreaded cv29.

 

more info as I work it out.

 

 

[96RAF]

Going back to the OP - How do I program an R8247 for continuous output to operate signal lights.

 

First a bit more clarification and correction of what has gone before - especially some of my earlier assumptions.

 

First thing to note is the continuous output of an R8247 has a current limit of 240mA total on all four ports, so given that once a port is fired it is effectively toggled on until toggled off, then the load on each port, all attached things being equal, should not be greater than 60mA.

 

The ON dwell time is factory default at 100mS or value 1 in the applicable port CV (see later) and is adjustable from 0 (always on) to 255 (on for 25.5 seconds).

 

As an aside from the OP - from this you can assume that an R8247 can be set to drive motorised points as well as solenoid points if the point motor load is less than the max allowable current and/or not more than one motor is running at once.

 

To accord with the NMRA rule set out in the document that Rog linked us to, for our purposes CV1 is the same as CV513, (CV2/514 is not supported by R8247 so we ignore it), CV3 is the same as CV515, and so on.

 

CV1/513 is the R8247 group address under the LSB situation and CV9/521 controls the address under the MSB situation. Unless we have a lot of points (see later) then we can ignore CV9/521. We can also ignore LSB/MSB for everyday purposes. 

 

The reason for the higher CVs is that addressing under NMRA using CV1 only supports up to 255 groups of points or up to 1020 actual point motors i.e. 255 x R8247s which should be enough for the average layout up to and including Fishy's large (i.e. double garage) definition.

 

The higher CVs allow for if CV9 is be set to enable address ranges 256 numbers higher than before i.e. setting Cv9 to value 1 adds 256 to the group address.in CV1 and puts this in CV513, giving a possible 510 x R8247s or points as far as address range 2041 to 2044. After that you may wish to start doubling up on a few ports.

 

CVs3-6 / 515-518 set the on duration of their associated port so it appears we can set different on times for each port within the range stated earlier including always on (Note - for solenoids never exceed a value of 8 (800mS) to avoid burning out the solenoid motor).

 

Back to the plot - assuming the use of an Elite and by way of the Menu system (see Elite manual for a handy flow chart of Menu events).

The actual programming follows this procedure:

Connect a load (solenoid or lamp) to port 4 of the R8247 and connect to the programming track. When programming is complete there is an output to port 4 indicating programming was successful. If using a solenoid then it is recommended to set the pin in the central position so that whichever way it is connected you will hear the clunk as it throws over.

 

Press Menu and Loco shows on screen - rotate speed knob until ACC shows - press knob again to select this option - Direct is shown - press knob to select this option.

 

Address is shown with Write below it (rotating the knob at this point allows you to select Read or Write) - press the knob to select Write.

 

Address will show with Adr:xxx below it (xxx is the last address used) Enter the address you want to use for the R8247 Group in our case we will use 1 or rotate the knob to show this number - press the knob to select this number and write it to the decoder. Port numbers 1, 2, 3 and 4 will be allocated to this R8247. The red led will flash usually 7 times to indicate programming has taken place and the point motor will throw over or the signal lamp will flash (if it flashes 8 times the programming has probably failed and you should repeat the procedure - sometimes several times is necessary). Note at this stage we are setting addresses and haven't set up ON times so the R8247 will be at 100mS default.

 

If you wish to confirm the addressing is OK then repeat the procedure but asking for Read instead of Write. The result you will see on screen is the Group number in our case 1.

 

For more R8247s you repeat this procedure after we have dealt with ON timing,  but Write address 5 to the second one, 9 to the third one, 13 to the fourth one and so on. Read back of these will be 2, 3 and 4 respectively  i.e. their Group addresses. 

 

Back to the first R8247 to set the on time:

Here we will Write to CV3 for port 1, CV4 for port 2, CV5 for port 3 and CV6 for port 4 to set individual ON times. Value 0 is required for always on, value 1 will pulse on for 100mS then off, value 10 will pulse on for 1 second then off, value 255 will pulse on for 25.5 seconds then off. Therefore we can set these ports to drive solenoids - short pulse, motorised points - longer pulse as required and signal lights - always on.

 

We can accord with NMRA rules if desired and write instead to CV515, 516, 517 and 518 - effectively the same thing so I will list both.

 

Press Menu - rotate knob to show ACC - press knob to select this option - Direct will show - rotate knob to show CV - press knob to select this option - Ensure Write is shown and press knob to select this option.

 

Enter CV number 3 or 515 using keypad or by turning knob then press knob to select . Enter value 0 (for continuous output in our case) and press knob to select. This value will write to the R8247. Repeat for CV4/516, CV5/517 and CV6/518 entering 0 for always on or your chosen on time.

 

Read back as before  to check programming was successful.

 

Repeat for any other R8247 using the same values as necessary.

 

You can operate a signal light in conjunction with a point by using 2 x R8247 (one for the solenoid and one for the signal) with both set to the same addressing, but with their timings set as appropriate to the load i.e. pulse for the solenoid one and always on for the signal lamp.

 

 

 

 

 

 

 

[grando4344]

r8247 - how many hornby R8014 points motors can you safely connect to one port  to work them together