ROTRONIC HF7 - Manual (Page 16)

E-M-HF7-V1_24
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
HygroFlex HF7 Humidity Temperature
Transmitters: User Guide Instruction Manual
Document Type
Page 16 of 23
Document title
© 2009-2011; Rotronic AG E-M-HF7-V1_24
7 Operation
7.1 Minimum load requirements for the HF73 with voltage outputs
The following requirements apply to any external device or circuit connected to the HF73 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 HF73 voltage output.
7.2 HF72 and HF73 transmitters (analog outputs)
If so desired, use the HW4 software to configure the HF7. Complete the mechanical and electrical installation
and simply power up the HF7.
HF73 output signal Input resistance RL
0…1V >=1kOhm
0…5V >=5kOhm
0…10V >=10kOhm
HF73 signal VCC R pull-up RL
0…1V 3.3V ≥ 250 kOhm 1 kOhm
HF73 signal VCC R pull-up RL
0…1V 5.0V ≥ 400 kOhm 1 kOhm
0…5V 5.0V ≥ 400 kOhm 5 kOhm
HF73 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
HF73
Voltage Output
R Pull-up
RL
GND
VCC
HF73
Voltage Output