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© Sealevel Systems, Inc. 7204e Manual | SL9244 11/2022
Hardware Configuration
There are two sets of 7-position dipswitches on the board that are used to set the electrical interface,
termination, and biasing. The dipswitch located at ‘SW1’ is labeled ‘PORT 1’ and configures the first serial
port. The dipswitch located at ‘SW2’ is labeled ‘PORT 2’ and configures the second serial port. The labels
and description of the function for each switch are detailed in the following table.
Dipswitch Settings
Switch
Description
M1
Sets the electrical interface mode (with M0)
M0
Sets the electrical interface mode (with M1)
T
Adds or removes 120
Ω
termination
PU
Adds or removes 1 K
Ω
pull-up resistor in RS-422/485 mode
PD
Adds or removes 1 K
Ω
pull-down resistor in RS-422/485 mode
L
Connects TX– to RX– for RS-485 two-wire operation
L
Connects TX+ to RX+ for RS-485 two-wire operation