AH500 Module Manual 12.6.6 PLC Programs Writing 【 Control program in master PLC 】 Write the program through the ISPsoft software After the master PLC runs and M0 is ON, write 500~505 to the corresponding D6000~D6005 in the master PLC respectively and the values in D6000~D6005 are sent to the slave through PROFIBUS. 12-50