16
Version 17
Safe-E-
Stop™
User Guide
4.
Frequency Selection
Reliable operation of the Safe-E-Stop system is dependent on the correct selection of one or more interference
free RF channels; inappropriate selection may lead to unexpected machine shut down. The Safe-E-Stop system
operating frequency is user configurable using a factory supplied program that can be run on a PC.
Depending on your region there may be licensed channels and/or license exempt channels available:
▪
Licensed channels provide the greatest level of signal reliability because issuance of channels is regulated
and controlled within the geographic region. When using licensed frequencies, it is absolutely critical that
only the RF channel assigned by your operating license be selected or you will be in violation of your Federal
licensing agreement and could be subject to Federally defined penalties.
▪
License-exempt channels are not regulated and hence the user needs to monitor and control frequencies in
use in their facility to prevent duplication within a building; there may also be other users off site but close by,
and these may be sources of interference; however, operation within a steel clad building will provide a high
level of isolation from these external sources. In an open site, however, you may be better off using licensed
channels.
It is the user’s responsibility to maintain a frequency plan to ensure interference free operation of the Safe-E-Stop
and other RF equipment on site. Selection of an appropriate operating frequency requires both knowledge of RF
channels in use and the application of the rules set out below.
Table 1: Frequency Spacing by RF band
B
AND
S
TART
F
REQ
H
Z
E
ND
F
REQ
H
Z
CH
S
PACING K
H
Z
S
TART
C
HANNEL
E
ND
C
HANNEL
C
H
,
S
PACING
A
418,000,000
B
433,077,500
434,777,500
25
A00
A68
2 (50kHz)
C
447,000,000
D
450,000,000
470,000,000
12.5
A00
Q00
4 (50kHz)
E
868,000,000
F
902,600,000
927,500,000
100
A00
C49
2 (200kHz)
Table 1
defines the six operating bands; currently Cattron has only released the B, D, and F bands.
▪
In North America, the D band is licensed and the F band is license exempt.
▪
Europe and many other regions including Brazil use the license exempt band B.
4.1 Rules for Frequency selection
1.
A channel can be any frequency between the Start Freq. and the End Freq. that is wholly divisible by the
CH Spacing.
−
Example: Band D channel 6 is 450,000,000 + (6*12,500) = 450,750,000.
And for any given frequency;
2.
If any other systems (including other Safe-E-Stop systems) are operating within 10m of the location that
the Safe-E-
Stop will be used, then a frequency that is at least as far away as is shown in the ‘CH
SPACING Separation’ column should be chosen.
−
Example: If another system is operating on 450,700,000 required minimum separation,
Table 1
is
50kHz so 450,700,000
– 50,000 = 450,650,000 and 450,700,000 + 50,000 is 450,750,000. Both of
these are within the Band Start and Band End frequencies. Make sure it is a valid channel according
to rule 1 above.
3.
Finally, make sure the derived frequency is not in the table below.
