Associated Products:

DS78V, DS78V

KB1072: Extra DS78V servo setup information

This article was last updated on Jan. 31, 2023, 12:08 p.m. | Print Article | Leave Feedback

  1. The Series7 Stationary (or Accessory) decoders are configured to not use, or need a CV Service Mode (SM) programming track. It is impractical to disconnect these fixed wired devices from a layout to configure on a SM track, unlike a mobile locomotive decoder.

    Series7 devices are configured when operating on a working LocoNet system to access all product capabilities.

    As detailed in the product Instruction Sheet (IS), the units have a number of Option Switches (OPSW's) that may be modified by; pressing the OPSW button and sending the appropriate SW# as Thrown or Closed. The IDSW button allows the setting of the board base address at any number, for a following sequence of addresses set by the device output count.

    This allows the primary setup and use on either a LocoNet system, or any DCC system that can send Switch commands.

    The product page and FAQ's cover additional details beyond the product IS, and any new features that may be added [or modified] with the latest product IPL/downloads.

  2. A DS78V and a DT602 both plugged into LocoNet allow a greater choice of modifying/checking Board Base address, Route setup and access to all settings.

    To access Accessory Operations Mode programming to modify specific Accessory CV's:

    On DT602 with latest code; press Menu>2>1 then the F (Switch) soft key to enter Accessory Mainline/Ops mode CV programming.

    Now the LH encoder changes the target Switch address by +/- 100, and the RH encoder makes a +/- 1 change.

    For example: a DS78V with base switch address = 3, uses the servo or output control range: SW#3 (output 1) to SW#10 (output8).

    Select the Ops Switch ADR address as this Base Address = 03 example.

    For Series7 devices CV1 to CV16 are reserved for controlling setups for the whole board (across all 8 outputs for a DS78V).

    CV17 to CV33 are reserved to modify just some individual output (channel) settings, chosen at the output selected by displayed Ops Switch ADR.

  3. For a DS78V individual servo output configuration setup:
    CV25 controls the THROWN servo angle (clockwise, looking at shaft). Default is 10. Range is 0-255.
    CV26 controls the CLOSED servo angle (counter-clockwise, looking at shaft). Default is 240. Range is 0-255.
    CV27 controls the APPROACH servo angle (e.g. Semaphore Mode mid/YELLOW). Default is 125. Range is 0-255.
    CV28 controls the APPROACH MEDIUM servo angle. Default is 125. Range is 0-255.

    Each step is about 1/2% of the typical 90 degree servo control range.

    You can invert or swap the THROWN/CLOSED angle settings for Output1 (SW#3) by e.g. selecting Ops Switch ADR = 3 and then changing CV25 = 240 and CV26 = 10. This example CV change will only affect output1 or SW#3 servo channel angles.

    To modify e.g. just DS78V output 8, select Ops Switch ADR to SW#10 and adjust CV25/26/27 for desired servo angles.

    For other DS78V's on the layout, simply use the correct (non-overlapping) switch numbers used by that unit, remembering that CV17 to CV33 are reserved to control individual output settings.

  4. If the DS78V is connected to LocoNet you can both READ and WRITE the Accessory CV settings and operate the DS78V, and you do not need a DCC track connection when using a DC power supply. Best practice is to not connect the DS78V DCC track terminals so you; don't consume Booster power when operating and are immune to track power disruptions.

    If the DS78V is only connected to DCC TRACK then the DT602 can WRITE Accessory CV's but not read back.

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