We programmed the controller with PC WORX 2. First we transmitted discrete values of current. Later we developed a programme to transmit current ramps.
Tuesday 15.07.2003
We tried the visualisation of the current. We checked for the word (16-bit) Hex number at the input and output. We notice some inaccuracy and reported this to our supervisor. He now asked us to document the error. We then prepared the hardware and programme for the testing.
Wednesday 16.07.2003
We carried out the test. We input a word (16-bit) Hex number to the analogue output. We observed the word value at the analogue input and recorded these details down. We took a total of 20 readings.
Thursday 17.07.2003
We converted the word (16-bit) values to their corresponding current values. We then made a spreadsheet with these values and calculated the error at each sampled value. We also plotted a graph representing the error against the input current. We notice that the transmission of current values fom 0 to 4 mA is very inaccurate, usualy resulting in error values of higher that 20%. Transmission of 4-to-20-mA currents have lower error rates, usually lower than 5%. We submitted out findings to our supervisor.
Friday 18.07.2003
We resumed our task to connect the two multiplexers via a telephone line. We were still stuck with the same symptoms, even if newer-firmware RS232-to-RS485 converters were used. Due to transportation arrangements we left the office at 13:00.
Saturday 19.07.2003
Visited Frankfurt.
Sunday 20.07.2003
Visited St Goarshausen to climb the Loreley Rock.