![Campbell CS120A Скачать руководство пользователя страница 20](http://html1.mh-extra.com/html/campbell/cs120a/cs120a_instruction-manual_488900020.webp)
CS120A and CS125 Visibility and Present Weather Sensors
8
4. Communications specification
4.1 Communications electrical specifications
Minimum
Value
Nominal
Value
Maximum
Value
RS-232 Communications
(1)
RS-232 input threshold Low
0.8V
1.5V
-
RS-232 input threshold High
-
2.0V
2.4V
RS-232 input absolute maximum
-15V
-
+15V
RS-232 input resistance
12K
-
-
RS-232 output voltage low
-
-
0.4V
RS-232 output voltage high (into
3K
)
4.4V
-
-
RS-485 Communications
RS-485 input threshold voltage
-0.2V
-
+0.2V
RS-485 output (Unloaded)
-
-
5V
RS-485 output (Load 50
)
2V
-
-
Maximum voltage at any terminal
(2)
-7V
-
+7V
(1)
The RS-232 communications interface will automatically turn itself off when not transmitting.
(2)
The ground of the sensor and the ground of any RS-485 equipment cannot be further apart than
this voltage. The sensor ground (pin 1) on connector B, see page 18, can be connected to the
ground of the host equipment. This will reduce any parasitic currents.
4.2 Supported data rates and formats
Serial setting
8N1
Supported data rates
1200 bps
2400 bps
9600 bps
19200 bps
38400 bps - default
57600 bps
115200 bps
Содержание CS120A
Страница 2: ...ii ...
Страница 4: ......
Страница 6: ......
Страница 8: ......
Страница 12: ...vi ...
Страница 73: ...A 1 Appendix A CS120A CS125 block diagram ...
Страница 74: ...CS120A and CS125 Visibility and Present Weather Sensors A 2 ...
Страница 76: ...CS120A and CS125 Visibility and Present Weather Sensors B 2 ...
Страница 90: ......
Страница 93: ...Appendix D Present Weather Codes D 3 ...