On 3/3/19 1:22 AM, Thaddeus Waldner wrote: > Maybe there was not so much dweeb in the Toshiba marketing department as > there was ignorance in the hobbyist integrator.... > > It turns out they don’t call the port an RS485 port; they call it a Toshiba > Inverter Protocol port. They sell converters that converts the Toshiba port > to either RS232 or RS485. These cost about $130 on ebay, which I don’t > necessarily want to spend. > I found this; > http://static.mah.priv.at/cnc/vfs11-rs232.pdf > > Can you or anyone enlighten me as to what is taking place with the Schmitt > trigger inverter and MAX232 chips?
IC1A and IC1D negate the serial data logic. Apparently the two systems use the opposite logic levels. The Schmitt triggers also have internal hysteresis to avoid false noise triggering that could cause erroneous data. IC1C and IC1E are being used as LED drivers for the blinky status lights. The MAX232 does the voltage level translation of the data signals. R1 and R3 are also used for voltage translation for the transmitted data. Apparently, J1 has 24 volt signals. C4, C5, C6 and C7 are used by the charge pumps in the MAX232 as flying capacitors to generate the +/- 10V used for the RS-232 signals. _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
