User`s manual

74 RabbitCore RCM3400
• RS-232—Two 3-wire or one 5-wire RS-232 serial ports are available on the Prototyp-
ing Board at header J5 and another two 3-wire or one 5-wire RS-232 serial ports are
available at header J6.
A 10-pin 0.1-inch spacing header strip is installed at J5 allows you to connect a ribbon
cable that leads to a standard DE-9 serial connector.
NOTE: An RS-232 driver chip needs to be installed at U5 along with a header at J6 and
filtering capacitors in order to use header J6.
• RS-485—One RS-485 serial port is available on the Prototyping Board at screw-termi-
nal header J4. Jumpers on header JP3 configure the termination and bias resistors.
• Current Measurement Option—Jumpers across pins 1–2 and 5–6 on header JP10 can
be removed and replaced with an ammeter across the pins to measure the current drawn
from the +5 V or the +3.3 V supplies, respectively.
• LCD/Keypad Module—Digi’s LCD/keypad module may be plugged in directly to
headers LCD1JA, LCD1JB, and LCD1JC. Appendix D provides complete information
for mounting and using the LCD/keypad module.
• IrDA—An infrared transceiver on the Prototyping Board is capable of handling link
distances up to 1.5 m. The infrared transceiver uses Serial Port F.
• Backup Battery—A 2032 lithium-ion battery rated at 3.0 V, 220 mA·h, provides
battery backup for the RCM3400 SRAM and real-time clock.