Ermes – Wavecom W74PC V8.7.0 User Manual
Page 173
WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0
Transmission Modes
163
If messages are not at hand, EFR periodically transmits time signals which allow the receivers to synchro-
nize their internal clock. From time to time, a test signal is transmitted containing the name of the trans-
mitter, e.g., DCF49.
EIA
The entire call number is transmitted by consecutive tones in decade sequence. When two identical digits
are to be transmitted consecutively, then an eleventh frequency is used as a repetition identifier.
Parameter
Value
Frequency range
VHF/UHF
Operation modes
Analogue Selcal
Modulation
FM, SUB Tones
Receiver settings
FM, BW = 12 kHz
Input format(s)
AF, IF
If more than two identical digits are to be transmitted, the repetition tone is appended to the digit tone
(e.g., 22222 is transmitted as f2 fw f2 fw f2, where f2 is the tone for "2" and fw is the repetition tone).
In most systems the accuracy of the single frequencies has to be within +1/-1.5% of the nominal value.
Decoding the selective calls is started by clicking on a system. If transmission and system selection con-
form, the call sign is displayed on the monitor. In the Options menu a Time stamp function can be ena-
bled to add date and time to each call.
Tone Allocation
Digit
Hz
Digit
Hz
0
600
8
1728
1
741
9
1869
2
882
A
2151
3
1023
B
2433
4
1164
C
2010
5
1305
D
2292
6
1446
E (REPETITION)
459
7
1587
Tone duration: 33 ms.
ERMES
ERMES is a Europe-wide high speed paging system with a user data rate of 6250 bps, in comparison to
POCSAG, which has a maximum rate of 2400 bps. ERMES radio data may be transmitted using frequency
or time multiplexing, or both. All transfer modes do however utilize the same modulation format on the
same frequency. ERMES is used in several European countries, whereas Asian countries tend use FLEX as
standard, which is a technically comparable Motorola system.
Parameter
Value
Frequency range
VHF/UHF
Operation modes
Broadcast pager
Modulation
4-PAM/FM
Symbol rate
3125 Bd