Error at programming time

[Mickey_Sadler]

Hi All,

The RS-232 standard states that -3 volts to -25 volts is a logic 1, and +3 volts to +25 volts is a logic 0. The -3 volt to +3 volt region is a "transition region" and a logic state is not assigned. Most computers supply -12 volt and +12 volt output, but some laptops only use around 4 to 5 volts + and - and this is not enough to drive some equipment. I have seen the same problem with some modems connected to a laptop serial port. Sometimes they worked, sometimes not, and sometimes just marginal communications. That's probably why your programmer worked on the PC and not the laptop.

Later,

Mickey