User manual

Chapter 3: Option Selection
The following paragraphs describe the functions of the various jumpers on the board.
A5 through A9
Place jumpers at locations A5 through A9 to set the board's base address on the I/O bus.
Installing a jumper sets that bit to a zero, while no jumper will leave the bit a one.
See chapter 4 of this manual for more details on selecting an available I/O address.
IRQ3 through IRQ15
Place a jumper at the location that corresponds to the IRQ level that your software will be able to
service. One IRQ services both serial ports.
485A/B and 422A/B
A jumper at the 485 location sets that port for 2 wire RS485 (Half Duplex) mode.
A jumper at the 422 location sets that port for 4 wire RS422 (Full-Duplex) mode.
For 4 wire RS485 applications install the 422 jumper if the port is the master, if the port is a slave install
both the 422 and 485 jumpers.
TRMI and TRMO
The TRMI jumpers connect the on board RC termination circuits to the input (receive) lines.
These jumpers should be installed for 4 wire RS422 mode.
The TRMO jumpers connect the on board RC termination circuits to the output/input lines.
These jumpers should be installed for 2 wire RS485 mode under certain conditions.
See the following paragraph for more details.
1
A5
A9
9
10
11
12
14
15
7
6
5
4
3
IRQs
P2
P2
485A 485B
422A
TRM I
TRM O
422B
TRM I
TRM O
ADDRESS
P2-COM A
P2-COM B
Figure 3-1: Option Selection Map
Manual 104-ICOM-2S, 104-COM-2S 13