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For DCC and Motorola IISwitches auxiliary functions like horn, whistle, light and smoke.Features• Multi-protocol function decoder for DCC and Motorola II• Suitable for the new DCC protocol for Function decoders, with up to 32000 special functions• 4 Function output with up to 0.6A capacity• All outputs can be individually configured for:- direction independent outputs- delayed outputs- blinking outputs• The outputs, when used in pairs, can be dimmed using PWM• Programming with a DCC or Motorola Digital centre• In DCC operation can be programmed by Register, CV or Page programmingDescriptionThe function decoder 73 900 is a small efficient Multi-protocol decoder. It can be used with DCCand Motorola-II Digital systems. The decoder cannot be used as a function decoder with the oldMotorola data format.The function decoder has 4 outputs with a load capacity of up to 0.6A each. For smaller loadswith voltage lower than 20V the output can be reduced when using the outputs in pairs (A1 andA2 as well as A3 and A4).The outputs can be configured individually. Each output can be activated for only one traveldirection. It can be programmed to switch on after a set time or switched on and off by a blinkgenerator.In analog operation you can determine which outputs are to be switched on. Directiondependent outputs are toggled by the DC power on the track.In the factory default state, the decoder automatically recognizes the DCC and Motorola dataformats as well as analog operation. The operation type can also be set up manually.Installation of the Function decoder 73 900Connecting the wiresWhen the decoder is installed in a vehicle, the blackwire is connected to the left wheel pickup (2-rail) or tothe vehicle chassis (3-rail). The red wire is connectedto the right wheel pickup (2-rail) or to the vehicle’s thirdrail pickup (3-rail).The loads are soldered directly to the circuit board ofthe decoder. As you can see in the diagram one sideof each load is connected to a function output and theother side to either the black wire (vehicle chassis) orthe solder pad for 20V return.73 900Fastening the decoder in the VehicleUse the double sided adhesive pad provided to fix the decoder to the desired location in thelocomotive. The adhesive pad protects the decoder from contacting conducting surfaces andholds it in place.Start-upDouble check the correct installation with a continuity tester or an Ohmmeter.When placing the device make sure it does not come in contact with any conducting surfaces inthe vehicle. Also ensure that a short circuit cannot occur when the locomotive is close and thatthe wire is not cinched.Digital operationAllocation of the special functions to the switching outputs via CV35 to 42In each case 2 CVs serve to allocate a function to an output. All functions from 0 (light) to32767 can be used (Motorola: 0-4, DCC: 0-32767). CVs 35, 37, 39 and 41 contain the highorder byte and the CVs 36, 38, 40 and 42 the low order byte of the function code.Calculation: Function number = high order byte x 256 + low order byteIf an output is to be switched by Functions 0-28, the high order byte must have the value of 128.Example 1: Special function f12 is to switch output A1.CV35 = 128 (factory setting)CV36 = 12For higher Functions the high order byte receives the appropriate CV.Example 2: Special function 2000 is to switch output A1.• Divide the address value by 256 (2000/256 = 7 remainder 208).• Enter the result (7) into CV35.• Enter the remainder value (208) into CV36.For Experts: The decoder controls all functions which are defined in the newest version of theNMRA DCC standard. Only the CVs 35 to 42 deviate from the NMRA DCC standard.There are the functions 0-28, as well as two further possible switching functions, for transfer toa vehicle decoder which is marked with Binary State control (BSC). If CVs 35, 37, 39 or 41(High byte) are given a value of 128 then the matching outputs of the decoder are controlled bythe DCC special function commands (0-28). If CVs 35, 37, 39 or 41 have a value smaller than128 the matching output of the decoder is controlled via BSC and function numbers 0-32767can be used. In this case (CVs 35, 37, 39 or 41 = 0) the outputs are also controlled via BSC iffunction numbers 0-28 are used.Direction dependent OutputsIn CVs 52 and 53 you can specify if the state of an output is to depend on the travel direction ornot. If the Bit for the respective output is set to “1” the output matching this CV directionsensing is turned off. CV52 is for the forward direction and CV53 is for the reverse direction,Delayed OutputsIn CV54 you can specify if an output activation is to be delayed or not. If the Bit for therespective output is set to “1” the output will be switch with a delay. The delay can be specifiedin CV55 in 0.5sec intervals. This delay is common to all outputs activated in CV54.Blinking OutputsIn CV56 you can specify if an output that is switched on is to operate on a blinking cycle or note.g. for a blinking light. If the Bit for the respective output is set to “1” then it will blink. CV57contains the time constants of the blinking cycle. A value of 1 means the output will blink 10times per second. A value of 10 means the output will blink on and off once per second. Thetime constants apply to all outputs that are set to blinking type in CV56.A short circuit with the Motor, lighting, third rail pickup and wheels can destroy thedevice and eventually the locomotive’s Electronics!Analog operationFor analog operation CV13 determines which outputs are switched on. Outputs that areprogrammed to be direction dependent in CV52 and CV53 will be switched independently of thedirection in DC analog operation.ProgrammingNote: So that the decoder can be read on a DCC programming track a load must be connectedto output A1.Configurations variables (CVs) form the basis of all programmable settings of the decoder inaccordance with the DCC standard. The decoder can be programmed with the Intellibox, DCCcentres and Motorola centres.Programming with the IntelliboxIrrespective of the format to be driven later we recommend that the decoder be programmed viathe programming menu for DCC decoders.The Intellibox supports DCC programming with a simple input menu. Long addresses do nothave to be laboriously calculated, they can be entered directly. The Intellibox automaticallycalculates the values for CV17 and CV18.For the exact process please read the appropriate chapter in the Intellibox manual.Special case decoder addresses 80 to 255 in the Motorola data formatThe Intellibox supports an address range up to 255 in the Motorola data format. Addresses 1 to80 can also be programmed (problem free) using DCC Programming. If, however, an addressabove 80 is to be used it must always be programmed as outlined in the chapter “Programmingwith a Märklin Centre”.After this programming is complete, the CV1 will contain a value of 0 and the decoder willrespond to a Motorola address above 80.Programming with DCC devicesUse the programming menu in your DCC Centre to program the decoder CVs in either register,direct CV, or page programming mode. It is also possible to program the decoder on the mainline using a DCC Centre.Refer to the manual of your control centre for full instructions on the process.Programming of long Addresses without the Programming MenuFor programming with a centre which does not support programming with an input menu, thevalue for CV17 and CV18 must be calculated. Here is an example for programming the address2000.• Divide the addresses by 256 (2000:256 = 7 remainder 208).• Take the result (7) and add it to 192.• Program this value (199) into CV17.• Program the remainder (208) into CV18.Important: Set Bit 5 of CV 29 to 1, so the decoder uses the long address.Calculating the CV valueIf several different settings on the decoder are to be changed in a particular CV, the value whichis to be entered is calculated using the CV table, and the values of the desired functions aresimply added.Example: Outputs A1 and A4 are to blink.OutputA1 blinks Value = 1OutputA2 does not blink Value = 0OutputA3 does not blink Value = 0OutputA4 blinks Value = 8The total value is 9.This value is programmed into CV56.
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