Through the CU8803 transmission box (recommended): Connect the CU8803 to a PC, and the transmission box simultaneously transmits video, USB, and 24V power to the panel via CP Link 4 cable (One Cable Display Link). At this time, it is not allowed to connect the independent power interface of the panel again, otherwise dual power supply will damage the equipment.
The CU8803 transmission box requires an external 24V power supply, and its power consumption calculation needs to consider panel power consumption (refer to technical data).

Mechanical installation and support arm adapter
3.1 Direct Installation and Adapter Selection
The rear shell of CP39xx has four M6 threaded holes, which can be directly installed onto third-party support arm systems. Beckhoff offers a variety of optional support arm adapters (pre installed or self installed) to adapt to Rittal or Rolec's 48 mm pipe diameter systems. The adapter can achieve ± 20 ° pitch and ± 165 ° rotation.
Ordering options (factory pre installed):
C9900-M750: Adapter facing upwards (cable introduced from below)
C9900-M751: Adapter facing downwards (cable introduced from above)
C9900-M752/M753: Version with button extension
Self installed adapter:
C9900-M761/M763: Requires adapter board C9900-M362 (for -0000) or C9900-M338 (for -0010)
3.2 Key points of installation steps
Open the adapter cover: Use a flat head screwdriver to pry open the bottom buckle, slide the cover upwards to expose the interface.
Install support arm tube:
Thread the connecting cable through the support arm tube.
Insert the support arm tube into the adapter to the stop position (50.2 mm deep).
Use a 3mm hex wrench to tighten the hex screw (torque 3 Nm).
Tighten the groove nut clockwise with a 58-62 hook wrench (torque 20 Nm).
Tilt and Rotation: The adapter allows the panel to tilt ± 20 ° and rotate ± 165 °, making it easy to adjust the optimal viewing angle.
3.3 Button Expansion and Cable Channels
If a button extension (C9900-G02x or G05x) is ordered, there will be a cable channel between the panel and the adapter. The channel cover (4 TX10 screws) and button expansion cover (7 TX10 screws) need to be opened before wiring can be done. For G02x model, the cable is introduced through M20 gland head; For G05x, use a 19 pin circular connector (Beckhoff provides prefabricated cables).
Power connection and grounding requirements
4.1 Power specifications
Rated voltage: 24 V DC (allowable range 22-30 V)
Plug: 4-pin M12, dual 24V/dual GND (parallel use can reduce contact resistance)
Wire cross-section: 4 × 0.75 mm ² (recommended for long-distance use)
Example of Voltage Drop Calculation (CP3924-0000):
Power consumption of 34 W, current of 1.5 A at 22 V
10 meter dual core 0.75 mm ² cable (back and forth 20 meters), copper resistivity 0.0178 Ω· mm ²/m → line resistance 0.475 Ω
Voltage drop=1.5 A × 0.475 Ω=0.71 V
The voltage at the power plug should be ≥ 22 V, therefore the output voltage of the power supply should be at least 22.7 V.
CP39xx-0010 with CP Link 4 has slightly higher power consumption (such as about 40 W for CP3924-0010), which needs to be calculated accordingly.
UL requirement: The power supply must comply with NEC Class 2 or be protected by a maximum 4A fuse (UL 248).
4.2 Protective Grounding and Functional Grounding
Protective Grounding (PE): The PE terminal inside the connection block or adapter must be connected to the central grounding point of the control cabinet using at least 4 mm ² wire to prevent dangerous contact voltage.
Functional grounding (FE): achieved through the same PE terminal, is the key to ensuring electromagnetic compatibility (EMC). Failure to perform functional grounding may result in touch screen misoperation, communication interference, and other malfunctions. The equipment meets EN 61000-6-2 (immunity) and EN 61000-6-4 (radiation) requirements.
Important: When using the CU8803 launch box, it is forbidden to supply power to the independent power interface of the panel, otherwise dual power supply will damage the equipment.
Cable Routing Guide
5.1 Adapter internal wiring (to prevent rotation damage)
The support arm adapter is equipped with a stress relief plate (with cable tie holes) inside. Wiring must be done in the specified order to avoid cables being pinched when the panel rotates/tilts:
For CP39xx-0000:
The power cable (thicker) runs on the outer side (right side), and the data cable (DVI Extended+USB Extended) runs on the inner side (left side).
Secure the power cable with zip ties to the two holes on the far right side of the stress relief plate.
Fix the two data cables together with zip ties in the leftmost hole of the stress relief board (using the first and third holes on the left).
For CP39xx-0010:
All cables (CP Link 4 cable, may have an additional independent power cord, but when using CU8803, there is only one CP Link 4 cable) are routed on the inner side.
When using a single cable, fix it with zip ties at the two leftmost holes; When two cables are used, fix them together with zip ties at the leftmost and third hole positions.
5.2 Additional stress relief plate (only -0000)
-The 0000 model power cable also needs to pass through an additional stress relief plate (located near the back of the panel). Thread the cable under the board and secure it to the board with zip ties.