Patton electronics 2002 Series User Manual page 9

Inverted Control and Non-Inverted Data Signals
Position JP2 horizontally on bottom jumper posts to select inverted
control and non-invert data signals. Figure 7 shows the position of the
jumpers on the pc board. Table 6 shows the relative signal levels.
TTL Side
Figure 7: Inverted Control and Non-Inverted Data Signal Jumpers
Table 6. Inverted Control, Non-Inverted Data Signals
Signal Level
0.0 to 0.4 Volts
2.4 - 5.0 Volts
Data Signals Control Signals
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8
JP1
JP2
RS-232 Side
inactive
active