Update (07.06.2018): Siemens has officially solved this issue with Rev 0406 of CPCX26.
Several years ago SIEMENS released the SICAM AK3, the newest version of its biggest and most powerful SICAM RTU. By doing so, the company aimed not only to facelift the older AK ACP, but also to cut product costs, thus making it more attractive to the market. One obvious step towards cost cutting was getting rid of the product specific TOOLBOX cable.
Working with the AK3 now only requires a USB A – USB mini B (5 pin) cable, with prices starting from under 3 euros. The connection between the TOOLBOX PC and the AK3 is built up using the SICAM 1703 USB driver, which is delivered together with the TOOLBOX installation kit.
Whenever the AK3 is attached to the PC, a virtual serial port is created in Windows. The number of this virtual COM port can be checked in Windows’ Device Manager, but actually the port settings in the TOOLBOX Presets do not need to be changed, as the TOOLBOX finds its way to the AK3 through the SICAM 1703 USB driver.
And that’s it, everything works fine, just as one would have a connection over TOOLBOX cable.
Well, I mean this is the optimal case.
Unfortunately this SICAM 1703 USB driver has a major issue: it is not compatible with USB 3.0 at all. And I do not mean by that the five pin hardware connection, or communication speeds, but the xHCI (Extensible Host Controller Interface) architecture itself.
The second part of the problem is, that the newest notebooks are not equipped with the older Enhanced Host Controller Interface (EHCI) anymore. These notebooks do still have USB 2.0 ports, but are controlled by the xHCI. And SICAM AK3 does not like xHCI. When plugged in, Windows 10 does not recognize the device properly, no virtual COM port is created, and a communication between TOOLBOX and the AK3 is not possible.
Actually the compatibility problem is not between the AK3 and Windows 10, but the host controller of the notebook's chipset. There are several new notebook models, which are equipped with both EHCI and xHCI. On those systems, even if the operating system is Windows 10, the SICAM 1703 USB driver works just fine when the SICAM AK3 is attached to a USB 2.0 port.
SIEMENS is going to release a new – USB 3.0 compatible – driver, but that probably won’t happen too soon. Until then, those who bought new and fancy laptops have the following options:
- building up the connection between the AK3 and TOOLBOX through remote operation. This could be a working solution unless all the PREs are used for some other communication.
- buying another notebook only to work with SICAM AK3.
- using a USB server.
Using a USB server
USB servers are small, smart devices, basically equipped with one ethernet and several USB ports. The idea behind is, that the devices connected to their USB ports can be shared over the network. Such kind of devices are often used in control cabinets to make remote maintanance works possible over a separate network (not the one of the industrial process).
But, how can a USB server be helpful in this particular problem?
In most cases, engineers use virtual machines to set up and work with TOOLBOX. This makes things simple: handles TOOLBOX version compatibility issues, keeps the project environment clean and secure, but most important the environment can be migrated from one PC to another in minutes.
By using a USB server and a Windows 7 virtual machine, Windows 10 and the xHCI can be bypassed, by directly assigning the USB ports of the USB server to the Windows 7 environment.
Following steps must be done:
- A Windows 7 virtual machine with TOOLBOX needs to be prepared.
- A good USB server is needed. Unfortunately not all of them are able to handle the SICAM AK3 device. First I have tried to do the trick with the somewhat cheaper SILEX DS-510, but it didn’t work out, the device blocked when I connected it to the AK3.
The USB-Server Industry Isochron developed by Wiesemann & Theis GmbH is not cheap, but will do the work.
This device needs a 24 VDC power source. Don't forget to order one together with the device, if another power source is not available. By default, the product is shipped without the 24V adapter.
- Building up the physical connections is easy: ethernet cable between the TOOLBOX PC and the USB server and USB cable between the USB server and SICAM AK3.
- Installing the necessary W&T software from the provided DVD:
– WuTility, for finding the device and setting its IP address
– W&T USB Redirector, for handling the USB devices connected to the USB server
- Setting the IP address of the USB server (with the WuTility) is not a must, as it is preconfigured with the address 188.8.131.52, just make sure that the host’s network adapter is bridged with the virtual machine, and the virtual machine is in the same network as the USB server.
- Use the USB Redirector to connect to one of the two USB devices.
Well, this is not a cheap solution, but carrying two notebooks on-site (one fancy and one to work with SICAM AK3) is not fun either.
And still, the USB server could be sold or used somewhere else, when the new SICAM 1703 USB driver is available.