Wavecom W74PC V8.7.0 User Manual
Page 172
162
Transmission Modes
WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0
If there 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
1981
8
1747
1
1124
9
1860
2
1197
A
1055
3
1275
B
930
4
1358
C
2400
5
1446
D
991
6
1540
E (REPETITION)
2110
7
1640
Tone duration: 40 ms.
EFR
A German company operates a radio broadcast load balancing and ripple control system for electrical
power distribution networks. Short telegrams are used to control street lights, heaters, tariff switching etc.
Parameter
Value
Frequency range
HF
Operation modes
Broadcast asynchronous ASCII
Modulation
FSK
Shift/Bandwidth
340 Hz
Symbol rate
200.0 Bd
Receiver settings
DATA, CW, LSB or USB
Input format(s)
AF, IF
The subscribers control their equipment by sending messages to the central computer of service provider.
The central computer forwards the messages to transmitters in Frankfurt am Main (DCF49, 129.1 kHz)
and Burg (DCF39, 139.0 kHz).
Transmissions are 200 Bd ASCII FSK with a shift of 340 Hz.
The transmission format is based on DIN-19244, i.e., start bit, 8 data bits, parity bit and stop bit. The
length of the data frame is variable; therefore a length field is required. The frames consist of a start
character, followed by the length information, which is sent twice. The fourth byte is the start character
again. Bytes five to seven are message number, address field A1 and address field A2. After a maximum
of 16 data bytes, a checksum is transmitted and finally the stop character. The checksum is an addition of
the message number, address and data fields without considering carry bits. Messages are sent twice to
increase transmission security.
Two user data protocols are in use, Semagyr-TOP and Versacom. As messages do not contain a protocol
identifier both formats are displayed together with the raw data string in hexadecimal format. Using Op-
tions/Display Mode... the display may be toggled between All frames and Error free frames.