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C.3.1 md485 multidrop interface configuration, C.3.1 – Campbell Scientific HMP155A Temperature and Relative Humidity Probe User Manual

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Appendix C. Interfacing with HMP155A RS-485 Output

Using HyperTerminal, send the following commands to the HMP155A:

VERS[enter] to get a response from the sensor; for example, HMP155A 1.26

SERI[enter] to get the current RS-485 settings; for example, 4800 E 7 1

SERI 9600 N 8 1[enter] to change the RS-485 settings; response should be

9600 N 8 1

R[enter] to put the sensor in the Run mode to output continuous measurements

Responses to the commands are shown in the screen capture below.

After the settings have been changed, change the baud rate in HyperTerminal

to 9600, and make sure the relative humidity and temperature string is being

displayed before connecting the sensor to the MD485.

C.3.1 MD485 Multidrop Interface Configuration

Using the Device Configuration Utility, configure the MD485 as shown below.

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