M-986-2R2
www.clare.com
3
Rev. 3
A Transmit Tone Command written while the transceiv-
er is in STATE 1 will be acted upon immediately. The
transmitter is unconditionally disabled upon entry into
STATE 2. If a transmit command is written to the trans-
ceiver while in STATE 2, that command will become
pending. Upon entry into STATE 1, a pending transmit
command is acted upon.
In backward mode, the transceiver can exist in two
states, STATE 1 and STATE 2:
STATE 1: No forward signal detected.
Transmitter off unconditionally.
STATE 2: Forward signal detected.
Transmitter transmits backward signal.
A transmit tone command written while the transceiver
is in STATE 2 will be acted upon immediately. The
transmitter is unconditionally disabled upon entry into
STATE 1. If a transmit command is written to the trans-
ceiver while in STATE 1, that command will become
pending. Upon entry into STATE 2, a pending transmit
command is acted upon.
EXAMPLE: Assume that the transceivers at both ends
of a link are configured in automatic compelled mode.
Both transceivers are in STATE 1. A compelled signal-
ing sequence begins with the R2F host writing a trans-
mit command byte to its transceiver via the
coprocessor bus. The transceiver immediately begins
transmitting the signal.
Automatic Compelled Mode Operation
Binary Coding Format
Byte
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Transmit tone command
1
CHN
0
A
B
C
D
Receive tone return
0
CHN
0
A
B
C
D
CHN: 1 = channel 2;
0 = channel 1
R2 MF Frequencies:
ABCD
Forward (Hz)
Backward (Hz)
ABCD
Forward (Hz)
Backward (Hz)
0 0 0 0
Tone off
1 0 0 0
1500 & 1860
1020 & 660
0 0 0 1
1380 & 1500
1140 & 1020
1 0 0 1
1620 & 1860
900 & 660
0 0 1 0
1380 & 1620
1140 & 900
1 0 1 0
1740 & 1860
780 & 660
0 0 1 1
1500 & 1620
1020 & 900
1 0 1 1
1380 & 1980
1140 & 540
0 1 0 0
1380 & 1740
1140 & 780
1 1 0 0
1500 & 1980
1020 & 540
0 1 0 1
1500 & 1740
1020 & 780
1 1 0 1
1620 & 1980
900 & 540
0 1 1 0
1620 & 1740
900 & 780
1 1 1 0
1740 & 1980
780 & 540
0 1 1 1
1380 & 1860
1140 & 660
1 1 1 1
1860 & 1980
660 & 540
2 of 6 Coding Format
Byte
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Transmit tone command
1
CHN
F6
F5
F4
F3
F2
F1
Receive tone return
0
CHN
F6
F5
F4
F3
F2
F1
CHN: 1 = channel 2;
0 = channel 1
R2 MF Frequencies:
Bit name
Forward (Hz)
Backward (Hz)
Bit name
Forward (Hz)
Backward (Hz)
F6
1980
540
F3
1620
900
F5
1860
660
F2
1500
1020
F4
1740
780
F1
1380
1140