CHAPTER 4: Configuration
Table 4-3. DIP-switch SW3 settings.
Switch | Switch | Port | Description | | RS-485 | RS-422 |
Setting | Number | | | | | |
| | | | | | | |
485 | SW3-1 | 1 | 485 | Mode (4-wire) | ON | OFF | |
NE | SW3-2 | 1 | 485 Mode, No Echo (2-wire) | ON | OFF | |
485 | SW3-3 | 2 | 485 | Mode (4-wire) | ON | OFF | |
NE | SW3-4 | 2 | 485 Mode, No Echo (2-wire) | ON | OFF | |
| | | | | | | |
NE = No Echo. In a two-wire setup, the receiver will not echo back the transmitted
data.
4.2.2 QUAD-PORTUSB HUB—RS-422/485 (IC1021A)
Each of the four DB9 ports on the Quad-Port USB Hub can be set as either RS-422 or RS-485. You do not need to set a jumper to select these options. Instead, you just need to set DIP-switches SW1, SW2, SW3, and SW4.
Switch SW2 and SW4 Settings
To select either RS-422 or RS-485, set the DIP switches labeled SW2 and SW4 on the circuit board (see Figure 4-3). Table 4-4 lists the possible settings for DIP- switches SW2 and SW4. You can also set termination, pull-up resistance, and pull- down resistance via these switches.
Figure 4-3. Switches SW2 and SW4.
NOTE
Switch positions SW4-1, 2, 3, 4, and 5 are for Port 1. Switch positions SW4-6, 7, 8, 9, and 10 are for Port 2. Switch positions SW2-1, 2, 3, 4, and 5 are for Port 3. Switch positions SW2-6, 7, 8, 9, and 10 are for Port 4.
