Power Supply Of The Encoder - Jetter JM-206-230 User Manual

14 Counting Input (Option)

14.2.4 Power Supply of the Encoder

The optional counter card supplies a voltage of 5 V +/- 5 %.
The EnDat encoders by Heidenhain have been specified to 3.6 through 5.25 V of
0.2 A max.. This results in a maximum voltage drop of
cable. The voltage drop can generally be calculated as follows:
This results in the maximum cable length or in a minimum cable cross section:
Given
Example:
At a cable cross section of 0.34 mm
l = 54.74 m or - at a cable length of 80 m - the following cross section is needed:
A = 0.55 mm.
By a double wiring arrangement, the cable length can be doubled.
98
ΔU γ A
l
= ----------------------- -
A
ΔU : Voltage drop in V
: Current consumption by the measuring device in A
I
n
: Cross section of the supply cable in mm
A
: Cable length
l
: Electric conductivity (for copper:
γ
U = 1.15 V on the EnDat
Δ
⋅ ⋅
2 I l
n
ΔU
= ----------------- -
γ A ⋅
⋅ ⋅
m
⋅ ⋅
161 ----------- - A
=
2 I ⋅
2
mm
n
2
⋅
2 I
mm
n
----------------- - l ⋅
= -------------- - =
ΔU γ ⋅ ⋅
161 m
m
56
---------------- -
Ωmm
2
, there results a maximum cable length of
2
)
2
Jetter AG