User Manual

9
STEP 1: Set the DIP Switches
The DIP switches on the TCC-120/120I are used to set the signal
transmission mode and to enable or disable the termination resistor. You
can configure for either 2-wire (RS-485) or 4-wire (RS-422/485)
transmission modes. Also note that your program and serial port should be
set to match the repeater’s settings.
NOTE
The TCC-120/120I has two sets of DIP switches—one set on the
top end and the other set on the bottom end. To ensure proper
data transmission, make sure that the two sets of DIP switches are
configured properly.
SW1—Switch 1 selects RS-422 or RS-485 mode. The default is “Off” for
RS-485 mode.
SW2—Switch 2 selects 2-wire or 4-wire RS-485 mode. The default is “Off”
for 2-wire RS-485. Note that if Switch 1 is set to RS-422 mode, then Switch
2 is inactive.
SW3—Switch 3 enables the terminator to 120 ohms. When enabled, the
120-ohm resistor prevents signal reflection during RS-485 transmission.
The default is “Off” to disable the terminator. If your particular application
does not require the termination resistor, simply disable it by setting Switch
3 to the off position.