Cables And Cable Lengths - Honeywell FE260 Operating Instructions Manual

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3.3.1 Cables and cable lengths

The cable length between the FE260 and the volume corrector (intrinsically safe circuits) may be up to 1000
m depending on the application. The following table provides an overview of the requirements, settings and
limits depending on the cable length:
Cable cross-sectional area for power supply
(Terminal "U")
Max. transmission speed
(Terminals "R" and "T")
Max. frequency on Outputs 1, 3, 4
(Terminals "DA1", "DA3", "DA4")
Maximum frequency on Outputs 2, 3
(Terminal "DA2")
*1) For cable lengths up to 100 m a total of two cables 4 x 2 x 0.5 mm² are sufficient for all intrinsically safe
electrical circuits. With a cable length of more than 100 m a separate cable 2 x 1.5 mm² must be laid for
the power supply to the volume corrector (Terminal "U"). The total diameter of each cable must not
exceed 10 mm.
*2) The transmission speed is set on the volume corrector under "Bd.S2" (address 02:0708.0). With an
FE260 with the option "Local interfaces" or "CL interface" the baud rate must be set to 9600 Bd
irrespective of the cable length. With "CL interface" also lower baud rates are possible.
*3) With long cables (clearly noticeable from about 100 m) the pulse-space ratio is degraded by the cable
capacity: The space (output transistor blocking) is shortened and the pulse (output transistor conducting)
is lengthened correspondingly.
If this effect causes problems, the pulse duration and the period (and also therefore the space duration)
can be altered for the volume corrector outputs with the aid of the "enSuite" parameterising program.
Example:
The standard setting is: Period 1000 ms, pulse duration 500 ms (giving a space also of 500 ms).
With a cable length of 1000 m the space is typically shortened by about 250 ms and the pulse is
lengthened by about 250 ms. The space duration is therefore about 250 ms and the pulse duration about
750 ms.
If the (theoretical) pulse duration is set to 250 ms instead of 500 ms with the period unchanged, then
actual pulse and space durations each of 500 ms are produced again including the degradations.
*4) Output 2 ("DA2") can also be operated, as can all other outputs, as a low frequency pulse output with a
frequency up to 10 Hz. Furthermore, some volume correctors in the LIS-200 range, such as the EK260
and EK280, offer the possibility of operating Output 2 as a high frequency output at up to 500 Hz. The
connection "DA2" on the FE260 is specially rated for this. Consequently, the above mentioned
degradation of the signal (see *3) is substantially less here.
*5) In case of FE260 manufactured since January 2014, output 3 ("DA3") can be used for signals up to 500
Hz. The EK280 offers the ability to operate not only output 2 but also output 3 ("DA3") as a high
frequency output under the same conditions as described for output 2 (refer to *4).
! The cable cores must be stripped 11 mm. They must be inserted into the terminal over a
length of 14 mm. Take care that only one core is inserted into each clamp!
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Only EK260s with a date of manufacture from July 2004 onwards.
Operating Manual
Cable length up to:
0.5 mm
19200 Bd
10 m 100 m
2 2
0.5 mm
19200 Bd
10 Hz 10 Hz
500 Hz 50 Hz
500 m 1,000 m
2 2
1.5 mm 1.5 mm
19200 Bd 9600 Bd
1 Hz 1 Hz
5 Hz 5 Hz
FE260
Rem.
*1)
*2)
*3) *5)
*4) *5)
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