Hi, I just noticed on the sample solution the data transfer time calculation is wrong? Take this sysconfig and commandfile for example # devicename readspeed writespeed # device terminal 10Bps 3000000Bps # timequantum 100usec # cal 10usecs write terminal 2000B 20usecs exit # The sample solution says: @00*0*0*6 device.terminal acquiring DATABUS, writeing 2000 bytes, will take 687usecs (20+667) Since it is mentioned that the data transfer rates are measured in Bytes/second, 2000Bytes with a speed of 3,000,000Bps will take 0.0006666.... This is practically 0 in the program. So if my understanding is correct, this data write should only take 20usecs, which is just to acquire the DATABUS.