User Manual

E-M-HF4-V1_22
Rotronic AG
Bassersdorf, Switzerland
Document code
Unit
HygroFlex HF4 Humidity Temperature
Transmitters: User Guide
Instruction Manual
Document Type
Page
19 of 29
Document title
© 2009-2011; Rotronic AG E-M-HF4-V1_22
7 Operation
7.1 Minimum load requirements for the HF43 with voltage outputs
The following requirements apply to any external device or circuit connected to the HF43 transmitter with
voltage outputs:
In the situation where the external device uses an internal pull-up resistor the value of this resistor should
meet the requirements shown below. It is also necessary to add a pull-down resistor RL connected to ground
in order to be able to read 100% of the range of the HF43 voltage output.
7.2 HF42 and HF43 transmitters (analog outputs)
If so desired, use the HW4 software to configure the HF4. Complete the mechanical and electrical installation
and simply power up the HF4.
HF43 output signal
Input resistance RL
0…1V
>=1kOhm
0…5V
>=5kOhm
0…10V
>=10kOhm
HF43 signal
VCC
R pull-up
RL
0…1V
3.3V
≥ 250 kOhm
1 kOhm
HF43 signal
VCC
R pull-up
RL
0…1V
5.0V
≥ 400 kOhm
1 kOhm
0…5V
5.0V
≥ 400 kOhm
5 kOhm
HF43 signal
VCC
R pull-up
RL
0…1V
10.0V
≥ 1 MOhm
1 kOhm
0…5V
10.0V
≥ 1 MOhm
5 kOhm
0…10V
10.0V
≥ 1 MOhm
10 kOhm
RL
GND
HF43
Voltage Output
R Pull-up
RL
GND
VCC
HF43
Voltage Output