Aalborg DFM Digital - Manual (Page 8)

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2.2.3 Communication Parameters and Connections
The digital interface operates via RS485 (optional RS-232 is available) and pro-
vides access to applicable internal data including: flow, temperature, pressure
reading, auto zero, totalizer and alarm settings, gas table, conversion factors and
engineering units selection, dynamic response compensation and linearization
table adjustment.
Communication Settings:
Baud rate: -------- 9600 baud
Stop bit: -------- 1
Data bits: -------- 8
Parity: -------- None
Flow Control: -------- None
RS-485 communication interface connection:
The RS485 converter/adapter has to be configured for: multidrop, 2 wire, half
duplex mode. The transmitter circuit has to be enabled by TD or RTS (depending
on which is available on the converter/adapter). Settings for the receiver circuit
usually should follow the selection made for the transmitter circuit in order to
eliminate echo.
RS-485 T(-) or R(-) -------- pin 11 of the 25 pin "D" connector (-)
RS-485 T(+) or R(+) -------- pin 24 of the 25 pin "D" connector (+)
RS-485 GND (if available) -------- pin 20 of the 25 pin "D" connector (GND)
RS-232 communication interface connection:
Crossover connection has to be established:
RS-232 RX
(pin 2 on the DB9 connector) -------- pin 11 of the 25 pin "D" connector (TX)
RS-232 TX
(pin 3 on the DB9 connector) -------- pin 24 of the 25 pin "D" connector (RX)
RS-232 GND
(pin 5 on the DB9 connector) -------- pin 20 of the 25 pin "D" connector (GND)