APPENDIX 3 ________________________________________________________________________
VAISALA ________________________________________________________________________ 113
Use command ? to find out the settings of the active transmitter:
? <cr>
DMP248 / 1.01
CPU serial nr : 0
Keyboard type : 0
Address : 7
Output units : metric
Baud P D S : 4800 E 7 1 FDX
Serial mode : STOP
Output intrv. : 0 min
Mtim : 32
Pressure : 1013.25
Analog outputs
Ch1 0.00 ... 10.00 V
Ch2 0.00 ... 10.00 V
Ch1 ( RH ) lo 0.000 %RH
Ch1 ( RH ) hi 100.000 %RH
Ch2 ( T ) lo -20.000 'C
Ch2 ( T ) hi 180.000 'C
Transducer :
PRB serial nr : 0
Calibr. date : 0
When the necessary settings have been given, close the line to
transmitters (the command closes all open lines):
>close
line closed
CLOSE command is always given without address. If no lines are
open, there will be no response to the CLOSE command.
POLL mode
If a transmitter has been set to POLL mode, it will respond only to
commands which include its address:
send 22
Td= -47.4 'C T= 29.1 'C
Addresses from 1 to 99 can be used. According to the RS 485/422
standard a maximum of 32 devices can be connected on same bus, but
the number can be increased if the line length and/or baud rate is
reduced.
The line terminations must be dynamic; e.g. an RC circuit is used
instead of a simple resistor termination. Each RS 485 module has a
dynamic line termination so it can be used at the end of a line.
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