Software installation and connections

WD-20EPFirmware: WD-20EP mount build; AHC 1.1.0 interface reference

WD-20EP uses the OnStepX control system, with support for OnStepX commands and compatible runtime configuration through the supplied firmware. This allows control from OnStep ASCOM, INDI and supported LX200 clients. For the underlying command system and configuration concepts, see the OnStep / OnStepX Wiki.

Generic OnStepX instructions describe many controller builds. Apply the ports, settings and firmware procedures in this WD-20EP manual to your mount; availability of commands depends on the installed firmware. WarpAstron-specific EC HA Limit and AEB are explained in Chapter 06.

In this chapter

• 4.1 Choose a control method
• 4.2 Install drivers and software
• 4.3 Wired connections
• 4.4 Wireless connections
• 4.5 Add the mount to control software
• 4.6 Use multiple applications
• 4.7 Disconnect and reconnect
• 4.8 Configure and use N.I.N.A.
  • Connect the mount
  • Time and location synchronization
  • Plate solving and guiding
  • Meridian flips
• 4.9 Saddle power and data
  • Port ratings and cable choice
  • Common power arrangements
  • Set up and verify saddle power
  • Port B as a mount PC connection

4.1 Choose a control method

Setup	Connection path
AHC alone	AHC → supplied controller cable → mount controller interface
Windows / N.I.N.A.	N.I.N.A. → OnStep ASCOM driver → USB data cable → mount PC port; see 4.8.
Telescope-side mini PC	Power on the mount from its DC input first; then use saddle Port B for data-only control through USB-A-to-USB-C, or for simultaneous PD power and mount data through USB-C-to-USB-C with a compatible mini PC. Avoid a second independent direct controller. See 4.9.
StellarMate / KStars / Ekos	Equipment profile → WARPDRIVE driver → mount PC port or supported TCP connection.
Other INDI clients	WARPDRIVE or LX200 OnStep driver → mount PC port or supported TCP connection.
ASIAIR	OnStep mount profile → USB data cable → mount PC interface
Wireless client	Compatible OnStep/LX200 TCP client → AHC Wi-Fi → wired AHC-to-mount connection

AHC supplies WD-20EP's advertised GPS and wireless functions. It must remain connected to the mount for its wireless bridge to relay mount commands. Joining its Wi-Fi network is not the same as opening a mount-control connection.

For StellarMate, connect the mount's PC port to the StellarMate computer by USB, create an equipment profile, and select WARPDRIVE as the mount. Start the profile, open the mount's INDI connection settings, select the detected serial device and verify the connection before movement. The StellarMate WARPDRIVE listing identifies its underlying driver as LX200 OnStep; see the detailed profile procedure in 4.2.

Begin with one wired connection and verify mount status before introducing additional applications or wireless control.

4.2 Install drivers and software

Windows / ASCOM

The USB serial driver, ASCOM Platform and OnStep telescope driver are three separate requirements. Install or confirm all three before configuring the imaging application.

1. 1. CP2102 / CP210x VCPUSB serial driver → detected COM port
2. 2. ASCOM PlatformCommon device interfaces and tools
3. 3. OnStep ASCOM driverMount-specific connection and settings
4. 4. Imaging applicationN.I.N.A. or another ASCOM client

1. Obtain the supported packages from WarpAstron's software page. For the serial driver, use the Silicon Labs CP210x VCP package, which supports the CP2102 USB-to-serial interface. If a working compatible driver is already installed, confirm it rather than reinstalling it unnecessarily.
2. With the mount secured and cables connected, power it from its separate DC supply. Connect PC to the computer with a USB data cable. In Device Manager > Ports (COM & LPT), identify Silicon Labs CP210x and record its COM number. Resolve any driver error or missing port before continuing.
3. Install a compatible ASCOM Platform. This provides the interfaces and diagnostic tools; it does not replace the telescope driver.
4. Install the supported OnStep Telescope ASCOM driver. Restart the application, or Windows if an installer requests it. A mount firmware update is a separate operation and is not needed just to install a PC driver.
5. Open the driver configuration as described in 4.5, select the recorded COM port, and verify status before commanding movement. Install N.I.N.A. or your chosen imaging application after the required driver stack is ready.

INDI / StellarMate / KStars / Ekos

Use an INDI distribution supported by your astronomy computer. WARPDRIVE is the WarpAstron mount selection; LX200 OnStep is an alternative compatible driver selection. These names refer to the INDI driver/profile, which communicates with the mount using its OnStep/LX200 command interface. Do not select two mount drivers for the same physical connection.

1. Connect the mount's PC port to a USB port on the StellarMate or INDI computer. Secure and power the mount separately.
2. In StellarMate's equipment profile, or the KStars Ekos Profile Editor, add WARPDRIVE as the mount/telescope. If that entry is unavailable in the installed distribution, select LX200 OnStep. Add the camera and guider required for your setup, then save the profile.
3. Start the profile and open the mount device in the INDI Control Panel. For serial connection, select the actual detected device and the firmware's baud rate. The standard reference PC connection uses 9600 baud; verify the supplied firmware instructions if it differs.
4. For a supported network connection instead, keep AHC wired to the mount and enter its actual TCP address and port from 4.4. The mount-command port is distinct from the INDI server connection used by the client.
5. Choose one source for observing time and location. Check the profile/client's update policy so an incorrect computer site does not overwrite valid mount or GPS information. After connecting, verify UTC, location, time zone, coordinates and tracking/Park state before a GoTo.
6. Save the working driver configuration. Test a supervised movement and plate-solve/Sync before enabling a sequence.

The official WARPDRIVE and LX200 OnStep listings identify the drivers. Configure WD-20EP-specific protection settings through AHC or a supported WarpAstron tool; a generic driver may not expose every vendor setting.

ASIAIR

Connect the mount's PC port to an ASIAIR USB port. In ASIAIR's mount settings select the supported OnStep / OnStep Electronic profile and the detected serial device. The legacy WarpAstron connection instructions and local mount configuration use 9600 baud for the PC interface; use the rate supplied with your installed WD-20EP firmware if it differs.

NOTE · ASIAIR profile selection — user feedback

Users have reported better results with OnStep Electronic than with other available OnStep selections in some ASIAIR versions. ASIAIR uses its own customized INDI driver build, so profile behavior may differ from upstream INDI / StellarMate. Treat this as a compatibility suggestion, not a guarantee: try OnStep Electronic when available, record the ASIAIR version and verify connection, status, guiding and a supervised meridian flip with your setup.

After connecting, verify time, location and reported position. Test the actual ASIAIR hardware/software combination before relying on unattended sequences. Do not accept a plainly incorrect plate solve or synchronization result.

4.3 Wired connections

CAUTION · Similar connectors, different interfaces

The mount's USB-C-shaped HC controller/ST4 interface is not an ordinary powered computer USB input. Use computer USB only at the front-panel PC interface or the designated saddle Port B mount-PC route. Saddle Port A is a power output. Use the supplied controller cable only at HC; an incorrect connection can damage the electronics.

Computer USB

The following sequence is for the front-panel PC port. The saddle Port B connection has a different cable and power-on order; follow 4.9 instead.

1. With the equipment stopped, connect a USB data cable between PC and the computer.
2. Provide the mount's separate DC supply and start the mount.
3. Confirm the computer detects the serial device. Note its assigned port; the port can change after a cable or USB socket change.
4. Select that port in the mount driver. For the standard reference PC interface, start with 9600 baud unless the firmware instructions specify otherwise.
5. Connect and read mount status and coordinates. Connection should succeed without a motion test.

A charge-only cable may power or enumerate other accessories but cannot provide the mount data connection. Do not assume USB from the computer replaces mount DC power. A computer mounted on the telescope may instead use the Port B data route.

AHC connection to the mount

With mount power off, connect the supplied controller cable between the socket at the top of AHC and the WD-20EP front-panel HC port. The top socket is above the screen; it is not the mount's PC port. Leave the joystick centered at startup and wait for the green mount-connection icon and live Dashboard data.

Advanced Hand Controller views. The mount cable connects at the top of the controller, above the screen; the socket is not visible in these front views. Connect its supplied cable to the mount's HC port.

AHC connection to a PC

For AHC-to-PC connection, use a fully wired (full-pin) USB-C to USB-C cable compliant with USB 3.2. Charge-only cables and USB 2.0-only C-to-C cables do not provide the required connection. If AHC is not detected, check this cable requirement before reinstalling software; see connection troubleshooting.

This requirement applies to the AHC-to-PC route. For direct mount computer control, use the mount's labeled PC interface. Do not connect computer USB to the mount's controller/ST4 interface.

Optional RJ12 / ST4 guiding

If a guide camera or specialist tracker requires a standard RJ12 ST4 connection, obtain the additional WarpAstron-compatible Type-C-to-RJ12 ST4 converter intended for use with AHC and this mount. Contact WarpAstron support or support@warpastron.com for compatibility, purchase and connection instructions. This optional converter is not a generic USB adapter. Follow its labeled connections and supplied routing instructions; confirm the pinout before connecting a guide output. An ordinary USB-C-to-RJ12 cable or USB hub is not a substitute.

For normal computer imaging, prefer pulse guiding over the USB ASCOM/INDI mount connection. The guide camera sends images to the guiding computer by USB, and the guiding software sends corrections through the mount driver; a separate RJ12 guide cable is normally unnecessary. Reserve ST4 for equipment that requires it, such as a compatible dedicated solar-tracking device. Do not run independent ST4 and pulse-guiding controllers simultaneously. See 5.7 Guiding.

4.4 Wireless connections

The AHC 1.1.0 reference provides a TCP command bridge at port 9999, with AP and STA Wi-Fi modes. Wireless availability can depend on the supplied regional configuration.

Wi-Fi settings in the AHC reference interface. Read the actual Mode, Address and TCP Port on your controller.

AP: connect directly to the controller

1. Keep AHC wired to the mount. Open Settings > Wi-Fi, enable Wi-Fi and select AP.
2. Read or set the AP name and password in AP Settings, then press Save & Apply.
3. Join that network from the control device.
4. In a client that supports OnStep/LX200 over TCP, enter the controller's address and TCP port.
5. Read mount status before issuing a command.

Reference defaults are SSID WARPDRIVE, password onstep-shc, address 192.168.0.1, TCP port 9999. Use the values currently shown by your controller if they have been changed. A device may warn that the AP has no internet; this does not by itself indicate a failed mount connection.

STA: join an existing network

1. Open Settings > Wi-Fi, enable Wi-Fi and select STA.
2. Open Network Settings, scan or enter the network name, and enter its password. Use a supported 2.4 GHz network.
3. Press Save & Apply and wait for STA Ready.
4. Read the assigned IP address from the AHC Wi-Fi page.
5. Put the client on the same reachable local network, then use that address and port 9999.

DHCP can assign a different address later. Check the display after reconnection. Network isolation or a firewall can prevent TCP control even when Wi-Fi association succeeds.

AHC wireless indicator	Meaning
Gray	Service is off, initializing, connecting or unavailable.
Light blue	Service is ready.
Green	A command client is connected.

Bluetooth

AHC uses BLE Nordic UART Service, not an assumed classic Bluetooth serial port. The client must explicitly support BLE and the Nordic UART Service; support for classic Bluetooth / SPP alone is insufficient. Pairing with the operating system does not establish software compatibility. In Settings > Bluetooth, enable the service, set the supported device name and optional six-digit passkey, then use Save & Restart. Reconnect the client after the controller restarts.

NOTE · Network changes interrupt control

Changing Wi-Fi mode, address settings or BLE configuration can disconnect clients. Stop the relevant operation first, apply the settings, reconnect, and read the mount's current state before resuming.

4.5 Add the mount to control software

Open the OnStep ASCOM configuration panel

This follows the ASCOM configuration procedure in the WarpAstron reference manual. Menu wording can vary with the ASCOM Platform and driver version.

1. Stop movement and close other clients that directly hold the mount's serial port.
2. Open ASCOM Diagnostics from Windows. Select Choose Device, set the device type to Telescope, and click Choose.
3. In the ASCOM Telescope Chooser, select OnStep Telescope (shown as OnStep in some versions), then click Properties. This opens the OnStep driver's setup/configuration panel.
4. For direct USB, select the mount's actual COM port and the supported baud rate. For AHC Wi-Fi, use the driver's supported network connection option and the actual IP address / TCP port. Keep these routes distinct.
5. Inspect time/location update options before connecting. Read each option's direction: sending PC information to the mount and reading mount information into the client have different effects. Apply the chosen source consistently; see N.I.N.A. synchronization.
6. Save with OK, return to the device test/application, and connect. If the setup panel provides a connection/status check, verify the returned mount information there as well.
7. Confirm operating mode, hemisphere, UTC, site, pointing coordinates and tracking/Park state. Only then perform a short low-speed movement in a clear direction and confirm that STOP works.

An imaging application's telescope setup / settings / Properties button can open the same driver dialog. Installing the driver makes it available in the chooser; connecting it in Diagnostics does not automatically connect a separate application. Disconnect the diagnostic session before moving to your imaging software.

WARNING · First software motion test

Remain beside the equipment during the first test. A successful connection does not prove correct coordinates, direction, limit settings or clearance. Check Chapter 06 before a GoTo or automated sequence.

If coordinates or state do not update, disconnect that application and use connection troubleshooting. Do not repeatedly send GoTo to diagnose a communication problem.

4.6 Use multiple applications

Plan the control path before opening multiple clients. For example, an imaging application can direct a shared ASCOM/INDI mount connection while guiding software sends guide corrections through the same supported driver/server.

Assign one source for site/time, one coordinator for GoTo and meridian flips, and one guiding controller. Verify your driver/server supports the intended sharing; two programs opening a physical COM port directly can conflict. If a hub is required, configure it to own the OnStep connection and connect the participating applications to that shared hub, rather than also opening the COM port independently.

CAUTION · Competing commands

AHC, a planetarium, N.I.N.A., ASIAIR and a guider can issue commands through different interfaces even when they do not share a COM port. Conflicting GoTo, Park, tracking-rate, time/location or flip commands can interrupt an observation or move the equipment along an unexpected route. Give motion ownership to one application during a sequence; keep the others read-only or disconnected. Local STOP remains available for an unsafe movement.

Wi-Fi and BLE command delay depends on signal strength, interference, distance and network stability. A delayed response is not proof that the command was rejected: inspect the actual mount state before repeating it. Prefer a verified wired route where reliable command timing matters. A wireless disconnect is not a stop command; see 4.7.

Before AEB Auto Tune, disconnect independent PC, guide-port and other control sources as specified in 6.5. The controller's guided workflow cannot guarantee exclusion of commands arriving at every independent hardware interface.

4.7 Disconnect and reconnect

For normal disconnection, stop the imaging sequence and guiding, complete the desired Park or stopped state, then disconnect the application before unplugging its data cable.

If communication is lost:

1. Inspect the mount directly and use local STOP if needed.
2. Check power, cable retention and the correct network address.
3. Close stale client connections and reconnect one controller.
4. Read actual movement, tracking, Park and warning states before any new command.
5. Check time, location and pointing if either controller restarted.

WARNING · Connection loss is not STOP

Tracking or slewing can continue after an application disconnects, Wi-Fi is lost or a display goes dark. Continued movement can trap hands or strike nearby equipment. Keep clear, use local STOP if needed, and verify the mount's actual state before handling the setup.

4.8 Configure and use N.I.N.A.

N.I.N.A. (Nighttime Imaging 'N' Astronomy) provides a Windows imaging workflow using the OnStep ASCOM telescope driver. This section covers WD-20EP connection, observing-data checks and a first imaging session. Menu labels may differ by N.I.N.A. release; use the official documentation for the installed version.

Connect the mount

1. Complete the three installations in 4.2: CP2102 / CP210x VCP, ASCOM Platform, and OnStep Telescope ASCOM. Install N.I.N.A. separately; installing N.I.N.A. alone does not install the OnStep driver.
2. Secure the setup, connect the mount's PC port to the Windows computer, and power the mount separately. Configure the driver as described in 4.5.
3. In N.I.N.A., create a profile for this equipment. Open Equipment > Telescope, refresh the device list if needed, and select the OnStep ASCOM telescope. Open its setup/settings button to confirm the COM port or supported network address, then connect. Do not select a simulator or an unrelated EQMOD driver.
4. Check reported coordinates, tracking and Park state without starting movement. Resolve any synchronization prompt as described below. Unpark only when the equipment and planned route are ready; connection alone is not a reason to start tracking.

See N.I.N.A.'s equipment connection guide and Telescope controls.

Time and location synchronization

Before connecting, check the Windows clock, date and time zone, then set the observing site in Options > General > Astrometry. Use the actual observing location rather than a saved home site; check hemisphere and longitude sign. See the N.I.N.A. General settings.

Choose the authoritative source before accepting any synchronization prompt:

Source you have verified	Intended direction	What to check
Imaging PC / N.I.N.A.	PC/client → mount	Correct Windows clock and N.I.N.A. site before allowing the driver/client to write them to the mount.
AHC / valid GPS information already applied to the mount	Mount → client, where offered	Read the verified mount site into N.I.N.A.; avoid overwriting it with an old PC profile. Verify time separately.

Read the prompt's source and destination rather than choosing a button by habit. A location-sync prompt is not proof that the mount's clock has also been updated. Date/time transfer depends on the driver's supported settings and selected policy. Inspect those options and verify the resulting UTC on AHC. A GPS fix also does not prove the correct time-zone setting; see 5.2 Location and time.

CAUTION · Verify the result before motion

After synchronization, compare site coordinates and time between N.I.N.A., the driver and AHC. Confirm the mount's UTC and time zone. Incorrect data can change target altitude, meridian timing and the planned GoTo/Park route. Stop if the displays disagree; do not use a GoTo or widen limits to compensate.

Site/time synchronization establishes observing data. A plate-solve Sync establishes the mount's relationship to the solved sky position; these are separate tasks.

Plate solving and guiding

1. Configure the imaging camera and a supported plate solver in Options > Plate Solving. Install the solver and any required catalog, set its executable path, and verify focal length / pixel scale. See the plate-solver settings.
2. Complete physical Home and polar alignment. Keep the telescope route clear before commanding any reference movement.
3. Capture and solve an image. Check that the solution is plausible, then send Sync to the mount using the plate-solving workflow. Slew and Center also commands motion; use it only for a target whose complete route is clear. Before its first GoTo after power-on, verify site/time and enable Tracking. A solved image without Sync does not initialize mount pointing. See N.I.N.A. plate solving.
4. For guiding, configure PHD2 with the OnStep ASCOM mount connection and connect N.I.N.A. to PHD2. Check that the driver or shared hub supports the chosen multi-application route. Calibrate and test guiding as described in 5.7.
5. Use a short supervised sequence to verify image download, solving, centering, guiding and a normal stop before extending the session.

Meridian flips

Open Options > Imaging > Auto Meridian Flip to set the behavior. In the Advanced Sequencer, add the Meridian Flip trigger to the relevant imaging container; options alone do not add that trigger. For a legacy sequence, enable the target's automatic-flip option. See N.I.N.A. automated flips and sequencer triggers.

Setting	Purpose
Minutes after Meridian	Earliest requested flip time after transit.
Max. Minutes after Meridian	Latest end of the exposure-dependent flip window.
Pause before meridian	Stops imaging/tracking before transit when the setup requires a pause.
Use Telescope Side of Pier	Use verified driver pier-side reporting for flip decisions.
Recenter after flip	Plate-solve and restore framing after the flip.
Scope Settle time	Allow movement/vibration to settle before the next operation.

For the setting definitions, see N.I.N.A. Imaging options. Configure settling and recentering only after the camera and solver work reliably.

Coordinate the whole flip window, including an exposure already in progress, with 6.3 Meridian limits and 6.4 EC HA Limit. Sidereal hour angle advances about 1° in 4 minutes; convert units carefully, but do not treat this as a fixed safe delay. The safe window depends on telescope/camera clearance, cables, firmware behavior and the encoder boundary. N.I.N.A. can request a flip after an exposure completes inside its configured window; if that request is late or never arrives, the mount's West-limit response is independent of the camera exposure.

WARNING · Supervise the first flip

Schedule N.I.N.A.'s imaging flip before the mount's West boundary; prevent another application from issuing a competing flip request. The mount's own enabled automatic flip can still occur at West as a fallback, including during an unfinished exposure. Remain beside the setup during the first complete flip and confirm pier-side change, target recentering, tracking and guiding recovery. If a limit stops the mount, stop the sequence and diagnose the timing/coordinates/clearance before continuing; do not simply widen the limit.

At session end, stop the sequence and guiding, confirm correct time/site and the plate-solve/Sync result, and use 5.9 Park. After Park completes, disconnect the software as described in 4.7.

4.9 Saddle power and data

WD-20EP brings two USB-C ports to the moving saddle for compatible telescope-side accessories. Identify each port by its marking and the figure below; do not infer its function from left/right position. These outputs do not replace the mount's separate DC input.

Interface locations, rendered from the WD-20EP model. Port A / CH1 is power-only; Port B / CH2 provides power and a mount USB serial connection. Confirm the markings on your own mount.

NOTE · Saddle PD remains live with the front-panel switch off

The saddle PD circuits receive power whenever a live DC supply is connected to the front-panel DC input. The front-panel switch controls the mount, not Port A/B power. A saddle accessory can therefore remain on when the mount switch is off. To de-energize the saddle ports before changing power cables, disconnect the front-panel DC input; do not rely on the switch or an unlit mount indicator. If Port B is connected to a computer, shut down a Port B-powered mini PC and unplug its USB cable first, as described below.

Solid arrows: power. Dashed arrows: mount USB data. The front-panel switch does not disconnect saddle PD. The two PC routes are independent; Port B is neither a bridge nor a USB hub. Use one independent computer control route.

Port ratings and cable choice

Port	USB-PD fixed profiles listed for WD-20EP	Other function
A / CH1	5, 9, 12 and 15 V up to 3 A; 20 V up to 5 A. PPS is listed up to 20 V / 6 A.	Higher-current power output. Use a compatible sink and a cable rated for the negotiated current; see the PD Hub arrangement below for a 6 A use case.
B / CH2	5, 9, 12, 15 and 20 V up to 3 A. PPS is listed up to 20 V / 3 A.	PD power output and an additional mount USB serial connection. A compatible mini PC can use both together. This is not a general USB hub.

The 12 V ceiling is nominal, not guaranteed at the accessory. Output may fall under load or cable losses. Higher profiles require sufficient actual input voltage and successful PD negotiation.

These are the manufacturer's published port capabilities, not guaranteed simultaneous output or fixed voltage at every connection. USB-PD requires a compatible source, sink and cable to negotiate the desired voltage. Check the accessory's input label and operating current. Do not assume that a device with a 5.5 × 2.5 mm barrel socket needs 12 V or uses the same polarity. Use a properly rated USB-C cable for 20 V / 5 A; an ordinary 3 A cable does not qualify. For PPS above 5 A, use a compatible device and a 6 A-rated cable, such as the cable supplied with the PD Hub; do not substitute a 3 A or 5 A cable.

Both saddle ports are step-down (buck) outputs; they cannot raise the voltage above the mount's actual DC input. With a 12 V input, the highest possible saddle output is nominally 12 V, so 15 V and 20 V PD profiles are unavailable. The supplied 12 V PD-to-DC leads cannot create a higher or more stable voltage than the source provides. Under load, conversion and cable losses can reduce the voltage available to an accessory; check the actual output before relying on a device that needs a regulated 12 V supply. Use the supplied 24 V adapter when an accessory needs a higher PD voltage or the intended full-power configuration.

The box includes two 1 m PD-to-DC leads with 5.5 × 2.5 mm device plugs: one rated 12 V / 3 A, the other 12 V / 5 A. The 3 A lead can use Port A or B. The 5 A lead belongs on Port A when a compatible device requires more than 3 A; using it on Port B does not increase Port B's 3 A ceiling. Confirm the polarity marked on each lead and the accessory before use. These leads are for accessory output, never for feeding the mount's DC input. A plain USB-C-to-barrel cable without the correct PD negotiation function is not interchangeable.

Common power arrangements

A compatible USB-C PD accessory can connect directly to Port A or B with a cable rated for its negotiated profile. For the supplied leads, optional PD Hub and compatible mini PC, use these arrangements:

Supplied 1 m 3 A lead: A or B. Nominal maximum 36 W, subject to negotiation and available supply; verify accessory voltage and polarity.

Supplied 1 m 5 A lead: A only. Nominal maximum 60 W; this lead does not increase Port B’s 3 A ceiling.

PD Hub: A, using the Hub’s 6 A-rated USB-C cable. Its up-to-120 W total rating requires the negotiated PPS profile and the complete power budget described below.

Compatible MeLE mini PC: B, with one USB-C-to-C power-and-data cable. Check the exact model’s combined PD/data support and Port B’s 3 A limit; follow the connection order below.

The device shapes are generic connection symbols. The PD-to-DC leads are accessory outputs, never mount input leads. For two separate 12 V accessories, use the 5 A lead on Port A and the 3 A lead on Port B; their individual ratings do not guarantee 60 W + 36 W continuously available together.

The PD Hub's top rating depends on Port A negotiating its published 20 V / 6 A PPS capability with a suitable 6 A cable. Port A's fixed 20 V / 5 A profile provides at most 100 W at the USB-C input before conversion losses; it cannot by itself supply a 120 W Hub load. The Hub has four DC outputs, with adjustable 5–19 V output settings (12 V default) and a 5 A per-output ceiling; the 120 W rating is shared across the Hub, not available at every output. The WD-20EP's 3 A and 5 A PD-to-DC leads do not connect to the Hub's USB-C input. The Hub's DC output sockets are 5.5 × 2.1 mm, unlike the WD-20EP leads' 5.5 × 2.5 mm device plugs; verify every downstream connector and the voltage configured for each Hub output channel before attaching equipment.

CAUTION · Power budget

The mount input is specified as 12–25 V DC, 10 A, and the supplied adapter is 24 V / 200 W. Add each connected device's maximum input power (volts × amps) and leave capacity for the mount, conversion losses and slew transients. Do not add the ports' separate advertised maxima and assume they can both be sustained at once. In particular, a Hub loaded to 120 W plus Port B loaded to 60 W already represents 180 W of accessory output before conversion losses and mount consumption; do not plan that combination against the 200 W adapter. A lower-voltage battery or current-limited source may further restrict high-voltage/high-current PD operation. If the input sags or the mount restarts, reduce accessory load and check the adapter, input plug and cable before continuing.

Set up and verify saddle power

Port B computer order. Shut down the mini PC normally before unplugging it. Saddle PD can remain live with the switch off; disconnect DC input to de-energize the ports.

1. With the front-panel DC input disconnected and any Port B computer cable unplugged, identify Port A, Port B and the DC input. Check that no socket or cable is damaged or wet.
2. For each accessory, record its required voltage, connector polarity and maximum current. Choose one of the arrangements above. Attach a non-computer PD accessory or PD Hub with its output devices switched off. Keep a Port B computer cable unplugged until the mount has DC power and is switched on. Provide a short strain-relieved loop at the saddle and keep the cable outside the dovetail clamps.
3. Keep the supplied AC adapter and all mains connections dry and protected from rain, spray, dew and wet ground. Do not use the adapter outdoors in damp conditions or where rain may reach it; see the AC adapter safety warning. Secure the mount and telescope, then connect the adapter's 24 V DC output to the mount input. The saddle ports can now supply PD power even though the front-panel switch is off. Do not connect a PD-to-DC accessory lead to the mount input.
4. Switch on the mount for AHC monitoring, then switch on the accessory. For a Port B computer, connect its USB cable only after this mount power-on step. Confirm normal startup. In AHC open Power to check input and CH1/CH2 voltage, current and watts; see 7.6. A reading of -- or zero without a valid device connection is not proof that the desired voltage has been delivered.
5. Add the next accessory only after the first is stable. Before changing saddle power wiring, stop motion and make the load safe, shut down any Port B-powered mini PC cleanly, switch off other accessories, unplug the computer cable from Port B, switch off the mount, and disconnect its DC input. Attach the next lead, restore DC power, and verify both devices and the total input load.
6. Test short supervised slews on both sides and a simulated meridian-flip path with all cables attached. Stop if a plug is pulled, a cable twists, an output drops or the mount restarts.

WARNING · Electrical fault

If a plug, cable or device becomes hot, sparks, smokes or smells of burning, stop movement and switch off the accessory and mount when safe. Disconnect the mount's DC input to de-energize the saddle outputs; the front-panel switch alone does not do this. Isolate the adapter, keep clear of the load path and do not retry the same cable or device before inspection.

Port B as a mount PC connection

Port B provides an additional USB serial channel for controlling the mount. It is not a bridge or pass-through from the front-panel PC port, and it is not a USB hub for cameras, storage or other telescope-side devices. A computer beside the tripod or pier can use the front-panel PC interface instead.

• Data-only PC connection: Use a USB-A-to-USB-C data cable, with USB-C at saddle Port B and USB-A at the computer. The ordinary A-to-C data cable does not supply negotiated USB-PD power to the computer.
• Combined mini-PC power and mount data: A compatible mini PC, such as a MeLE model with a USB-C port that accepts PD power and carries USB data, can use one USB-C-to-USB-C cable to receive power from Port B and access its mount USB serial channel. Use a data-capable C-to-C cable rated for the negotiated current; a charge-only cable will not carry mount commands. Check the exact mini-PC model's USB-C power input and data capabilities and Port B's 3 A maximum before use.

Install the supported mount driver, then confirm the computer detects the Port B mount serial interface and reads coordinates before any slew. Do not expect the front-panel PC port or any camera USB device to appear through Port B.

CAUTION · Connect mount DC power before computer USB

A powered computer may feed current back into an unpowered mount through the Port B USB connection. Connect the WD-20EP's DC supply and switch on the mount before connecting either PC cable to Port B. For the data-only route, then connect the USB-C end to Port B and the USB-A end to the computer. For a compatible combined-power mini PC, then connect the rated USB-C-to-USB-C cable; the mini PC may power up as soon as it is connected because saddle PD remains live. At shutdown, stop motion, disconnect the control application and shut down a Port B-powered mini PC cleanly. Unplug the computer cable from Port B before switching off the mount or removing its DC supply. Do not use computer USB power as a substitute for the mount's DC input.

When Port B carries power and mount data together, the negotiated voltage/current and combined input-power budget still apply; monitor CH2 and confirm the mini PC stays powered during slews. Do not connect two independent computers to the front and saddle PC routes at once or let separate applications issue conflicting movement commands; see 4.6. If Port B data does not enumerate, check the cable's data capability, the mini PC's USB-C role and the mount driver. Use the front-panel PC route for diagnosis rather than trying random USB-C hub adapters.