CalAmp ITC 220 User manual - page 48
ITC 220 Base Station, Locomotive & Wayside Radio Transceiver Field Service Guide PN 0046300120 Rev. A
| Page 42
To key up a Wayside transmitter at π/4DQPST half rate:
1. In XtermW type the following commands:
STOP
SCHED,DEL,ALL
DSP_MODE,IDLE
DSP_MODE,TEST
L1_TEST,SET,TXFREQ,value
L1_TEST,SET,TXMOD,DQPSK_HALF
L1_TXDUTY,3500,300,0
where:
value equals the desired frequency of operation in Hz.
Note: The ratio of 300/3500, specified for Wayside Transceivers, denotes approximately a 9% transmit duty
cycle. (The maximum transmit duty cycle for Wayside Transceivers must be held to less than 10%.)
2. Once observation of radio performance is complete, turn off transmit operations by typing:
L1_TEST,STOP
Note — The two following figures in this section show a typical transmission spectrum or power measurement of a
Wayside Transceiver at Half-DQPSK.
Figure 26 Typical transmission spectrum (Half-DQPSK)