Download User Manual PROGRAMMABLE REMOTE INPUT/OUTPUT

SiAM CRIO v3.0
User Manual
5.4.- Communication resistors
Switches 5-6-7 from the upper DIP-switch bank,
shown in the picture on the left, control the
communication resistors for RS-485 bus:
Jumper
S5
Description
Pull-up
resistor
(390 Ω)
S6
Pull-down
resistor
(390 Ω)
S7
Bus-termination
resistor (220 Ω)
Comments
Stabilizes the bus. Must
be active in only one
node in the RS-485
network.
Stabilizes the bus. Must
be active in only one
node in the RS-485
network.
Prevents reflections in
the bus. Must be active
only in the terminal
nodes in the bus, and
inactive in the all the
intermediate nodes.
These switches are hardware switches, so they
can be toggled at any time (not only in start-up).
All theses switches are useless in the RS-232
version of the board.
5.5.- Reset switch
Switch 8 in the upper switch bank is used to perform a hardware reset of the board
microcontroller, without the need of removing and reapplying power to the whole board.
The microcontroller is continuously reset while this switch is OFF.
This can be very useful to quickly update the configuration of the board –modbus address,
baud rate- after any change in the configuration switches.
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