Mode select configuration – Impulse 2801 User Manual
Page 8
Configuration
Sealevel Systems SeaLINK+8 Page
5
Below is a figure of dipswitches SW1, SW2, SW3, and SW4. Each switch has a
total of twelve positions and serves to configure two ports. Six positions are
used for each port. The default mode of RS-422 4-wire full duplex is shown.
ON
1
2
OFF
3
4
5
6
7
8
9
10
11
12
PORT 1
PORT 2
SW1
M0
M1
T
PU
PU
PD
MODE
M0
M1
T
PU
PU
PD
MODE
ON
1
2
OFF
3
4
5
6
7
8
9
10
11
12
PORT 3
PORT 4
SW2
M0
M1
T
PU
PU
PD
MODE
M0
M1
T
PU
PU
PD
MODE
ON
1
2
OFF
3
4
5
6
7
8
9
10
11
12
PORT 5
PORT 6
SW3
M0
M1
T
PU
PU
PD
MODE
M0
M1
T
PU
PU
PD
MODE
ON
1
2
OFF
3
4
5
6
7
8
9
10
11
12
PORT 7
PORT 8
SW4
M0
M1
T
PU
PU
PD
MODE
M0
M1
T
PU
PU
PD
MODE
Figure 1- Dip Switches SW1 - SW4 RS-422 Default Mode
Mode Select Configuration
The first two positions for each port are used to select the electrical interface
mode. In RS-422 mode the transmitter and receiver are always enabled.“485
WE” refers to RS-485 mode with receiver echo. In this mode the receiver is
always enabled. If the card is in 2-wire mode, all transmitted data will be
“echoed” back. “485 NE” refers to RS-485 mode with no receiver echo. In this
mode the receiver is enabled only when no data is being transmitted. In either
RS-485 mode the transmitter is only enabled during data transmission. Refer to
the chart below for specific switch settings. Note that this chart appears in the
silk screen on the board as well.
SWITCH
232
MODE SELECT
422
485 WE
485 NE
OFF OFF
M1
M0
OFF
OFF
ON
ON
ON
ON
Figure 2- Electrical Interface Mode Selection