I attempted to use a pair of serial extender devices and they did not work for me. They did not work because they only transmit RX, TX, RTS, CTS. The particular device I needed to communicate with, requires RX, TX, DSR, DTR. So I made my own serial cables which route DSR/DTR to the normal RTS/CTS pins, and that did not work either. I tried every possible combination of crossover/straight through, on both ends, nothing worked.
I confirmed that they DO work, so long as both devices are configured to use RTS/CTS, but the devices will not transmit a DSR/DTR signal the same way. I concluded that the two signals must be fundamentally different in some way. They are both digital signals, correct? Are the levels different? Is one a pulse train rather than a steady signal? What's the difference?
I confirmed that they DO work, so long as both devices are configured to use RTS/CTS, but the devices will not transmit a DSR/DTR signal the same way. I concluded that the two signals must be fundamentally different in some way. They are both digital signals, correct? Are the levels different? Is one a pulse train rather than a steady signal? What's the difference?