WSI, WSDI, WSS or WSS-L
User’s Manual
DEIF A/S
Page 15 of 19
The receiver is connected to instrument type WSDI with a 2-wire screened cable. Terminal "A" is
signal and terminal "B" is return (0V).
The NMEA 0183 standard requires the following signal levels:
"1" between -15 and +0.5V
|Isink|
≥
0mA
"0" b15 and +4V
|Isource|
≥
15mA @ +4V
The instrument type WSDI releases the following levels:
"1" -9.5V +/-0.5V
|Isink|
≥
1mA @ -8V
"0" +9.5V +/-0.5V
|Isource|
≥
15mA @ +8V
Please notice that NMEA does not request that the output may settle power in "1" condition, but
it is permissible. This is used in WSDI in order to make it compatible with RS-232C/V24.The
NMEA 0183 signal is inverted like RS232.
The "A" and the "B" signals are galvanically separated as prescribed by NMEA.
An RS232C receiver may be connected. Applicable would be a PC with the following
configuration:
Transmission speed
4800 Baud
Number of data bits
8
Parity bits
None
Number of stop bits
None
Number of connected receivers to the NMEA output
According to NMEA the receiver must be able to operate with a minimum differential voltage
input of 2V and must not take more than 2mA from the transmitter. Based on this information the
number of receivers connected to WSDI can be calculated.
The NMEA output in the WSDI is based on a 15mA constant source generator with an internal
voltage of 9.5V.
Max. receivers: 15mA/2mA = 7.5. This means that 7 receivers can be connected, if the receiver
input is made according to the NMEA standard.
Type numbers
Wind sensor Type WSS
Interface box Type WSS interface box
Display
Type WSDI
Spare parts
The following are recommended as spare parts (not included):
2 pcs.
Fuse F1, 0.1AT, Ø5 x 20mm (item no. 1020500010)
2 pcs.
Fuse F2, 1AT, Ø5 x 20mm (item no. 1020500006)