Blog3 - EN

2 Years Monitoring of Telemetry Modules of a Water Supplier

For more than 2 years we have been observing a telemetry network applied at a fresh water pipe network of our local water supplier.

Our system is running full automatically and supplies reports to our customer that includes the battery charge levels of the applied modules.

The Frontend is designed as modern Single Page App that runs at each modern browser. It shows battery charge levels, battery changing intervals and the GSM-signal. Furthermore all values can be prepared graphically and shown as time chart.

The Backend is using a data base server that shows more than 100.000 entries already. Consequently the relevant values can be observed automatically and errors be seen. The battery charge states of the data log devices are separated to 3 levels what helps to optimize service trips, saves driving time and consequently costumer’s money.

Extension of a FFU Control Centre

Recently a great research company in the north of Hamburg enlarged its cleanroom capacities. Therefore FFUs with EC-fans from Nicotra||Gebhardt were purchased that should be integrated to the existing FFU-Control-Centre. The owner purchased this service directly from us. We are delighted about such jobs, as they are normally executable without major tools. Hence the trip can be scheduled climate-friendly and comfortable by train. Rarely more than a  control device , to scan the FFU-lines with the ec-drives, and a laptop is required.

At the end there were only winners, the costumer was getting professional first-hand service, Nicotra||Gebhardt appreciates it’s FFU-control-partner, we have been able to do some day-to-day business utterly relaxed at the train trip and not to forget our environment.

Particularities of Brushless-DC Motors – Part II

… recently we reported about Brushless-DC Motors, that worked, driven be the overpressure in a cleanroom, as generators. The charged, along the back-emf diodes of their IGBTs, the DC-link at least partly that the switching power supply and therewith the communication started. As there is no correct charge of the PFC this is an undefined state so the mainly created FF-command sequences interfered the Gateway where the units still were connected to. The Gateways however interpreted this wrong and was brought out of step.

The solution was rather simple, a slight modification of the interrupt routine (IRQ) was done just to block the interrupt at the crucial point. So from now on the Brushless-DC drives can operate as Brushless-DC Generators and talking half asleep to the network without interfering their proper working colleagues.

Remote Commissioning of a S7-Controll for a Cooling System

Due to the pending quarantine regulations in China that requires a couple of additional days if not weeks, we decided to go for a remote commissioning of a cooling system together with our partner Kälteconcept using Skype and Teamviewer.

The plant itself, a subcritical CO2 Fluid-cooling-appliance was in central china, used in a wind tunnel of a Chinese Automobile Company, is designed for up to 850 kW cooling power. It consists of 2 parallel compound lines with 3 CO2 compressors each, partially controlled by VFDs.

Practically it was done with Tia-Portal V15 on a S7-1500 CPU with a TP900 Comfort-panel. The special feature is a Pre-Error-Archiv was saves, in case of a fault, all relevant system data for the last 30s BEFORE the error occurred.

Finally it was a total success with only winners. The end user saved some money and was practically forced to an intensive training, we avoided a long commissioning trip with a unpleasant quarantine and finally the environment wins by avoiding flight traffic. A random view at the sky above our house compared to one on feb. 21rd in 2012 speaks for itself.

Particularities of Brushless-DC Motors – Part1

It’s known, that the commissioning of larger projects takes longer and not anything can be expected in advance. One of our big FFU partners experienced this at firsthand. Normally the FFUs with its EC-Motors, that partner calls Brushless-DC Motor, will be mounted, wired and the belonging controllers individually addressed and finally powered-on section wise. Afterward the line will be scanned by a special control tool for those brushless-DC Drives, a possible wrong addressing corrected, followed by a short test run launched by control device whether anything is ok. At the end of this procedure you “get” a line that is addressed correctly and capable to communicate. Finally the line will be set to sleep per Stop-command, and not via power-off, for being ready for higher tasks.

If now, due to what reason ever, most of the FFUs with its Brushless-DC drives run at nominal speed the cleanroom will be set under pressure. Subsequently those fans being simple powered-off start to run in reverse mode. Now the Brushless-DC Drives show their particularities. The Brushless-DC Motor starts to windmill and operates as generator and charges via the reverse diodes the DC-link of the controller as long as the internal power supply and therewith the BUS-communications start to “work” or better to get to half asleep. The sent order sequences are a kind of half correct signal noise that is overlay the normal communication of the FFUs that are running powered-on at normal speed, what we are supposed to filter now. ... to be continued!

Cleanroom catalogue - ebmpapst

The most important point seems to be that there are special parameter sets for each of the relevant BUS systems (ebmBus, ebmBus/DCI as well as Modbus and Modbus/DCI) what allows a line wise mixed operation of these different fans at one single FFU-Control-Centre. This is especially relevant for plant expansion.