This projekt currently includes two pieces of software:

The code inside the here used microprocessor is written in Assembler to use the limitted resources of it in the, hopefully, best way.

programmstruktur.pdf programmstruktur.pptx

Main task of Mircrocontroller (MC) firmware is simple to count every inside movement of the pressured air drive to report that either at the eight digit local display or remotly to the far distance PLC unit. It has to stores that value in its built in none versatile EEPROM memory in case of power down. Microprocessor has to detect therefore beside the movement of the drive with “INSIDE” command although the power status of the primary 24V supply. In case of power loss a big capacity board of PA-Terminal insures for nearly one second power for the MC. That is enought to execute an interuped used to store important values. Of cause counter value is although storedin accelerator control system, but becuse GSI/FAIR accelarator is an experimantal facility number and places of air pressured driven diagnostic devices micght vary of the years or might be replaced for repair it important to store number of movements although within drive itselfes: the built in velded steel vacuum bellow has a limitted live time as it is a mechanically stressed part. This life time can be observed by the counter and maintance personal can observe that value.
PA-Terminal can interact remotly with a set of currently eight instructions about the system internal RS485-fieldbus. The command surly mostly used will be the request for the counter value. A comand that will be used properbly only one time is to set the ID or serialnumber of a that from 0-9999. If an on board jumper is kept open during power on that ID is let 0! Adressed by that first birth ID the SN can be set the a new destination number, although sored in none versatile memory. during operation the MC does continiously redundancy tests of the actual stored values. Each of them is stored three times and should any of it varry from its other two redundany places it will be corrected and a counter for values will be increased. That might occure because the PA-Terminal is postioned at the drive close to the beamline where in some cases hard radiation might be present. In that context a instruction for setting a counter value for correction meight although be useful if a missfit to values in accelerator controll system might be detected. As already mentioned the drives are proactive maintained. So during that times accelarator can be accessed an it makes sense to toggle on the local display of drive for on side controlls. In hopfully very rare cases the stored ID of a connected but not accessable drive might be loss: then the complete adress space can be requested for response to identify it again and restoring the original SN. The last two instructions are for requesting number of ouccured redundancy errors or setting it back to zero.

This code establishes network access to communicate through the LANTRONIC(TM) modul about the RS485-fieldbus to all the PA-Terminals connected to the bus. Cause of the fix and low data transfer rate of 9600 Baud (8N1) the long distance cable to a vacuum chamber with up to 6 drives / PA-Terminals might reach length of 1,6km (Structure see although RS485 -bus for counter control).