Serial communication settings, Caution – Vaisala DM500 User Manual
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User's Guide ______________________________________________________________________
74 __________________________________________________________________ M210205EN-D
CAUTION
The dip switches behind the DMI500 MUST NOT be touched,
because the processor may be destroyed as a result of false dip switch
positions.
NOTE
Before connecting a PC to DMI500 or DMP501, make sure there is
no ground potential difference between PC and the DM500.
Serial Communication Settings
Connect the DM500 to PC by using a serial cable (provided). When
connecting EIA-232 (RS232), use the port called 'SERIAL'. When
connecting optional RS485, use the port called 'RS485/LON'. Connect
the RS485 as follows:
Table 2
4-Wire Connection
Terminal
Data Line
1
R+ (input to DM500) ←
2
R- (input to DM500) ←
3
T+ (output from DM500) →
4
T- (output from DM500) →
5
Shield
Table 3
2-Wire Connection
Terminal
Data Line
1
R/T+ connect the same line to
terminals 1 and 3
2
R/T- connect the same line to
terminals 2 and 4
3
R/T+ connect the same line to
terminals 1 and 3
4
R/T- connect the same line to
terminals 2 and 4
5
Shield
Select the DM500 communication mode and data transfer settings as
follows:
1.
Open
MENU
: press .
2.
Select ►
Interfaces
, press .