Campbell Scientific HC2S3 Temperature and Relative Humidity Probe User Manual
Page 39
Appendix C. HC2S3 Digital Communications
C.4 RS-485 Communications using an SDM-SIO1
Serial I/O Module
The HC2S3 can be interfaced to a CSI datalogger through an SDM-SIO1 Serial
I/O Module using the Rotronic E2-05XX-MOD RS485 cable as described
below.
The example program uses the SerialOpen instruction to configure the SDM-
SIO1 for RS-485 half duplex, “COMport 32” at 19200 baud, no parity, 1 stop
bit, and 8 data bits, and serial instructions to send the RDD command to get
temperature and relative humidity data from the probe.
Sensor Wiring:
E2-05XX-MOD
Cable
SDM-SIO1
CR1000
Blue
Z
Red
Y
Gray/Yellow
G
Green
12V
Clear
Ground
SDM-SIO1 Wiring:
SDM-SIO1 CR1000
C1
C1
C2
C2
C3
C3
G
G
12V
12V
If the Rotronic cable includes brown and white wires (voltage
signals for temperature and humidity), CSI recommends
“capping” them with PN 27749 or equivalent insulated caps to
prevent the possibility of shorting.
NOTE
C-5