Teledyne 400E Instruction Manual page 119

Model 400E Ozone Analyzer
Instruction Manual
To allow the analyzer to be used with terminals (DTE's), modems (DCE's) and
computers which (can be either,) a switch mounted below the RS232 connector
allows the user to flip the function of pins 2 & 3.
P/N 04316 Rev: B
Operating Instructions
119