Convert SPKG interface board from RS-232 to RS-485/422

Use these instructions to convert the SPKG interface board from RS232 operation to RS485/RS422 operation. 

1. Set the "CS" parameter to 1. This should be done while the board is configure for RS232 operation so that it is easier to connect to a PC. Use either a terminal program or the X-CTU (XCTU) software. (Modem Configuration tab -> press "Read Module" -> Select the CS parameter from the list and choose setting of 1-RS485 -> click "Write module".)
2. Remove the RS232 chip (U10) - part # SIPEX SP312ACP.
3. Install the RS485 chip (U2) - part # MAX3080ECPD.
4. Install the following jumpers appropriately:
   1. J1 - Installed: 100ohm termination resistor placed across RX+ and RX- lines; Not installed: no termination resistor.
   2. J7 - Installed: RS485 half-duplex (2-wire) mode; Not installed: RS422, RS485 full-duplex (4-wire), or RS232 mode.
   3. J8 - Installed: RS485 half-duplex (2-wire) mode; Not installed: RS422, RS485 full-duplex (4-wire), or RS232 mode.
   4. J11 - Installed across pins 1 & 2: RS422, RS485 full-duplex (4-wire) mode; Installed across pins 2 & 3: RS485 half-duplex (2-wire) mode; Not installed: RS-232 mode. (Note: Pin 1 of J11 is closest to DB-9 (J2) connector.)