RS-232↔RS-422/485 CONVERTER (DATA ONLY)
3. Configuration
Here’s how to configure the RS-232↔RS-422/485 Converter (Data Only) for your application (refer to Figure 3-1 on the next page for the location of components on the circuit board):
CAUTION!
The Converter’s circuit board can be damaged by static electricity, so take every reasonable precaution against it. Always discharge yourself on a metal surface before opening the Converter or touching the board; if possible, stand on an anti-static mat and wear a grounding strap or anti- static gloves.
1.If your Converter is a standalone IC107A-R3 or IC107AE-R3 model: Open the Converter by unscrewing the single screw on the bottom of its case and taking the top of the case off.
2.Set the Converter’s RS-232 port to DTE or DCE as necessary for your application. For the RS-232 port to function as a DTE device, put the DIP- switch block in jumper socket XW1B. For the RS-232 port to function as a DCE device, leave the DIP-switch block in jumper socket XW1A (the factory- default setting). Whichever socket the block is in, make sure that all of its individual DIP-switch positions are always set to ON.
3.Set jumper W15 to select how the Converter’s RS-422/485 driver is enabled. If you want the driver to be permanently enabled, place the jumper across W15’s pins B and C. If you want to use the RS-232 DTR or RTS signal to enable the RS-422/485 driver, leave W15 in its factory-default position with the jumper across pins A and B. (To have DTR enable the driver, leave jumper W18 in its factory-default position with the jumper across pins A and B. To have RTS enable the driver, place the W18 jumper across pins B and C.)
4.Some applications require the RS-422/485 interface to be terminated. A resistor network can provide this termination on the Converter at the
RS-422/485 input receiver pins (RXA and RXB). Use DIP switch S2 to enable or disable termination: If you move S2 to the “TERM” position, the resistor network is connected across the line, and the RS-422/485 interface is terminated. If you leave S2 in its factory-default “UNTERM” position, no connection to the resistor network is made, and the interface is not terminated.
