huopio@lut.fi (Kauto Huopio OH5LFM) (08/31/90)
If anyone has easy scematics for a converter from current-loop rs-232 to "normal" rs-232, please e-mail here. Our cs club got a printer that works on current-loop rs-232 and our HP 9000/550 speaks just normal rs-232.. I guess that there is a chip that does it all :-? --kauto -- ****************** Kauto Huopio (huopio@kannel.lut.fi) ********************** *US Mail: Kauto Huopio, Punkkerikatu 1 A 10, SF-53850 Lappeenranta, Finland * *****************************************************************************
wayned@wddami.spoami.com (Wayne Diener) (09/02/90)
>In article <HUOPIO.90Aug31115619@kannel.lut.fi> huopio@lut.fi (Kauto Huopio OH5LFM) writes: >If anyone has easy scematics for a converter from current-loop rs-232 >to "normal" rs-232, please e-mail here. Our cs club got a printer that I've used the following circuit successfully. I'm not aware of any IC's that do it directly --- Current Loop Side Logic Side +5 ___ | 4N28 +5 R -------- ___ R 2.2K RS232 driver (inverting) 1 | | 6 | R |\ + (source) -----| |--------- |--------| o-----> 2 | | 5 10K |/ C |/ - (sink) -----| |------RRRRR-------| 2N222 3 | | 4 |\ E No Conn. ---| |------RRRRRR---|----| -------- 180K | --- \ / (gnd) --