Panel PCs for wall installation in cleanrooms – What you need to know

CONTROL: Rückseitige Montage mit Edelstahlrahmen (Option 2) (Bildrechte: Systec & Solutions GmbH) / CONTROL: Installation on the rear with a stainless-steel frame work (Option 2) (Image Rights: Systec & Solutions GmbH)

CONTROL: Flächenbündige Montage (Option 1) (Bildrechte: Systec & Solutions GmbH) / CONTROL: Fush-mounted installation work (Option 1) (Image Rights: Systec & Solutions GmbH)

MODI Rauminformationsanzeige - auch zur frontseitigen, flächenbündigen Montage geeignet (Bildrechte: Systec & Solutions GmbH) / MODI Room information display - as well suitable for flush mounted installation from the front (Image Rights: Systec & Solutions GmbH)

Tabelle 1

Table 1

Tabelle 2

Table 2

Integrating an HMI system in a cleanroom wall is among the classic installation options that enjoys particular popularity. Due to the deep design of older generations of HMI systems, wall installation provided the opportunity to install the system in a manner that is elegant, space-saving, and above all easy to clean. Since devices are now becoming increasingly sleeker and lighter, other installation options also offer ergonomic benefits. However, the flush-mounted display undoubtedly remains the option that can be cleaned the quickest. In the following, Systec & Solutions will present the questions that customers should ask before opting to install a panel PC.

Where should the panel PC be installed?

The conditions of the wall are crucial. You need to know whether it's a thin, classic cleanroom/system wall, a sealed dry wall, or a glass or solid wall.

Panel PCs can generally be installed without problems in the former. However, it is important to check if the wall has sufficient load capacity to securely hold the screen in question. It may be necessary to mechanically reinforce the wall first.

If your cleanroom has a dry wall, you must individually decide if a panel PC can be used. Since a dry wall tends to break out, it makes it difficult to create clean installation recesses. Systec & Solutions recommends using a suitable installation frame.

In the case of a glass or solid wall, it is not possible to use an HMI system in the wall. In these circumstances, there are other installation solutions such as floor or ceiling installation, or you can use mobile operating stations.

Of course, a panel PC can also be installed in a switch cabinet. 

Which panel PC installation versions are there in cleanrooms?

Generally speaking, panel PC installation versions can be divided into flush-mounted installation in the cleanroom wall or installation with a stainless steel-frame, making it slightly protrude from the cleanroom wall. The variant with the frame can be installed from the rear or from the front.

Option 1: How does flush-mounted installation work?

Flush-mounted installation requires a recess in the cleanroom wall and rear studs to which the device is screwed on from the rear. The wall must be accessible on the rear. The recess must be accurate to the millimeter and precisely match the manufacturer's specifications to create an even joint to be filled with silicone. In addition, an inconsistent recess would not look very appealing. This type of installation is therefore the most complex one and is particularly ideal for new constructions in which the wall should already have the appropriate recesses. Once the existing joint has been sealed with silicone, the cleanroom is closed again.

By the way: Systec & Solutions has developed a special installation system for the 7- and 10-inch displays of their MODI series that enables flush-mounted installation, even without having access to the rear of the wall. The mounting frame has magnets that hold the device that is inserted on the front. No screws are required, and it can easily be removed from the front again by using a suction cup.

Option 2: How does installation on the rear with a stainless-steel frame work?

If the rear of the wall is accessible, installation on the rear with a stainless-steel frame on the front is the simplest installation option. Once the recess and drilling pattern have been created, the device and frame with the welded stud bolts are inserted from the front and screwed in from the rear. By doing so, no screw heads are visible. The joint to the wall is sealed with silicone or sealed with an attached sealing cord. In this case, the recess must also be made according to the manufacturer's specifications, although it offers far more tolerances since smaller deviations can be covered by the frame. This variant is particularly useful for existing production sites, as the recess can be easily made in the wall afterwards.

Option 3: How does installation on the front with a stainless-steel frame work?

For installation on the front, there is no need for rear access to the cleanroom wall. A recess in the wall and the corresponding drilling pattern with the blind rivet nuts placed in the wall are required for installation. The device and the stainless-steel frame are inserted from the front and screwed in. The joint to the wall is sealed with silicone or sealed with an attached sealing cord. In this case, the recess must also be made according to the manufacturer's specifications, although it offers far more tolerances since smaller deviations can be covered by the frame. This variant is also particularly useful for existing production sites, as the recess can be easily made in the wall afterwards. Please note that with this solution, the screw heads must remain visible. It is easy to clean, but not as easy as with the other two options.

Now, which option is the best?

That depends on your requirements and situation. All solutions are exceptionally space-saving. The flush-mounted version is the easiest to clean, although it entails the greatest amount of installation work. In this case, a good compromise is installation on the rear with a stainless-steel frame. You should consider installation on the front with a stainless-steel frame only if you do not have access to the rear and have extremely confined spaces. (see table 1)

Where do the required cables run?

Ideally, the cabling runs inside the wall, therefore making it invisible and posing no risk of contamination. Systec & Solutions strongly advises against wiring outside the wall for the sake of cleanability.

What should you be aware of if a panel PC needs to be replaced in the cleanroom?

Please bear in mind that the drilling patterns in the wall are specific to the device and model. When replacing the unit, it may therefore be necessary to modify the installation recess and the drilling pattern. Changing to a smaller display means that the resulting difference must be compensated for. In addition, the cleanroom must be opened during replacement and subsequently be released for production again.

To make replacement easier for you, Systec & Solutions has developed a special protective enclosure for the CONTROL series. The device is inserted into this enclosure and installed as usual. The cable feeds are designed in accordance with protection class IP65. If replacement is necessary, the silicone joint is removed and the device can simply be removed from the enclosure without creating an opening in the cleanroom wall.

How do my employees use the display?

You can obtain panel PCs with and without a touch display. Your employees can conveniently control the screen via touch. However, if the application in use does not allow for that because, e.g., an on-display keyboard requires too much space or the selected display does not have touch functionality, a keyboard can be added. Ideally, this is installed below the device using a torque hinge on the wall, allowing the cables to be run into the wall. They can then be ergonomically adapted to the user or folded away in a space-saving manner if needed.

Connecting a separate keyboard or a mouse to, e.g., a shelf would require an external USB port or a cable outlet. In both cases, cleaning is far more difficult. A Bluetooth connection can be implemented, but please bear in mind that the batteries must be regularly charged in a timely manner to prevent outages.

How can my employees authenticate themselves?

An interface is required in order to enable simple release processes, such as via an RFID card or the Nymi band, and some keyboards already have this built in. Alternatively, Systec & Solutions offers a supplementary installation variant of the CONNECT BOX which is subsequently positioned next to the screen. This can also be flush-mounted like the panel PCs or mounted with a stainless-steel frame.

Which screen is the right one for my application?

The screen size, the technical equipment, and the position of the device depend on the device's application. If you only want to display the cleanroom status, then a smaller model is usually sufficient for you. To that end, Systec & Solutions offers the MODI series with 7 and 10-inch diagonals. If the MES system or other applications are to be controlled by your employees, a larger display is recommended, as it makes it much more ergonomic and easier to operate. For these applications, Systec & Solutions recommends the CONTROL series, available from 17 to 32 inches. When making a choice, always observe the software manufacturer's device resolution requirements. (see table 2)

You can find the complete technical data and more information on the MODI and CONTROL series on the corresponding product pages.

CONTROL: www.systec-solutions.com/en/products/hmi-systems/control
MODI: www.systec-solutions.com/en/products/hmi-systems/modi