[comp.sys.sun] RS232 WARNING

wyatt@cfa.harvard.edu (Bill Wyatt) (11/21/89)

> [...]
> Best Power Technologies carries a complete line of on-line UPS's for all
> sorts of equipment. They have an RS-232 port and Sun software that does
> all of this quite nicely. [...]

We have a Best UPS and are quite happy with it. HOWEVER, be warned that
the 25-pin D connector is not quite standard RS232. True, pins 2, 3, and 7
are as usual, but there are OTHER VOLTAGES on other pins (for external
alarms and the like).

DO NOT, repeat DO NOT connect an ordinary RS232 cable to your serial port.
Make a special cable with only those three signal lines!

Bill Wyatt, Smithsonian Astrophysical Observatory  (Cambridge, MA, USA)
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