ROTRONIC HM4 - Manual (Page 23)

E-M-HM4-V0_08
ROTRONIC AG
Bassersdorf, Switzerland
Document Code Unit
HM4 Humidity and Temperature Probe with
Heated Sensor
Instruction Manual
Document Type
Page 23 of 41
Document Title
© 2014; ROTRONIC AG E-M-HM4-V0_08
6.2 Wiring
This section describes the wiring of the device with connection possibilities.
6.2.1 Electrical Diagrams
The HM4 is connected with the 7-pin Tuchel
connector or the connection cable with open ends.
The maximum permissible cable length depends
on the voltage drop caused by the flow of current
to the devices connected to the HM4 outputs. The
effective load of a HM4 output comprises the cable
and load resistance and should amount to at least
1000 Ω/V (for voltage outputs according to Figure
3). The cable resistance should not be more than
1/1000 of the load resistance.
Figure 3: Voltage outputs
The maximum permissible length of the cable
connecting the unit to other devices is determined
by the total resistance resulting from addition of
the cable resistance and resistance of the devices
connected to the unit in series. This resistance
should not exceed 500 ohm (load) (for current
outputs according to Figure 4).
Figure 4: Current outputs
DRAFT