Fiso EGD-LT, Руководство пользователя

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EasyGrid LT User Guide
21
4.12.2 RS-485/RS-422 Ports
A RS-485/RS-422 serial port is provided on the EasyGrid LT. It can be used to connect the EasyGrid LT to
any RS485 or RS422 communication bus. It also allows multiple EasyGrid LT to be link together.
IMPORTANT
When linking many EasyGrid LT on the same party line, make sure that all units have a different network
ID. The factory-defined address for all units is one (1).
The port is accessible using the dedicated terminal block.
The pin layout is the following
A set of dip switches is used to configure the port. They are located at the right of the terminal block. A
sticker is provided to secure the dip switches after configuration.
Switch
RS-422 Mode
RS-485 Mode
RS422/RS485 Must be Left Must be Right
RS422/RS485 Must be Left Must be Right
RS485 EOL R Must be Left
Right : Adds a 120Ω End of Line resistor
Left: No end of line resistor
RS485 Pull Up Must be
Left
Right : Adds a 1kΩ pull up resistor
Left: No pull up resistor
RS485 Pull Down Must be Left
Right
: Adds a 1kΩ pull down resistor
Left: No pull down resistor
FISO recommends shielded, twisted pair wiring, 24 AWG with 120Ω line impedance to connect the RS-
485 interface to the network.
FISO also recommends biasing the RS-485 BUS using pull-down and pull-up 1 K Ω resistors. Biasing the
RS-485 BUS line will prevent unknown voltage on these lines (RS-485 BUS floating). Leaving the RS-485
BUS floating may result in conditioner communication failure.
Label
RS-422
Mode
RS-485
Mode
B+ RX + Data +
A- RX - Data -
B’+ TX + Do Not Apply
A’- TX - Do Not Apply
GND Ground Ground