8
The two sets of DIP switches on the underside of the Model 590A/591A
will be referred to as S1 and S2. Figure 2 shows the orientation of DIP
Switches S1 and S2 with respect to “ON” and “OFF” positions.
Figure 2.
Close-up of DIP Switches Showing ON/OFF Positions
Selecting the DTE Output Signals (DTR or RTS)
Use Switches S1-1, S1-2, S2-1 and S-2-2 to connect either Data Termi-
nal Ready (DTR - pin 20) or Request to Send (RTS - pin 4). In the “Iso-
lated” setting, the selected signal passes through Model 590A/591A
isolated up to 2500VRMS.
Table 1:
Connect DTR Signal (Pin 20)
Switch
Isolated Signal
Setting
S1-1
DTR
On
S1-2
DTR
Off
S2-1
DTR
On
S2-2
DTR
Off
NOTE:
Default Settings
Table 2:
Connect RTS signal (Pin 4)
Switch
Isolated Signal
Setting
S1-1
RTS
Off
S1-2
RTS
On
S2-1
RTS
Off
S2-2
RTS
On
1
2
3
4
5
6
7
8
ON
ON
OFF
