IMAGENEX DT101Xi, Technical Manual

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Doc no: 430-041-01 47 of 64
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Communication parameters are set as follows in the SIR unit:
Item Settings
Baud rate 19200
Number of bits 8
Stop bit 1
Parity bit None
Supported strings Valid NMEA ($GPGGA, $GPVTG, $GPZDA and optional $HEHDT)
Table 6-3
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Power is available on Pin 18, Pin 20 (12 VDC or 24 VDC option depending on jumper setting (see
Figure 6-8)) for powering of GNSS if required:
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In addition to GNSS data, it is possible to configure this port to accept GPS derived heading and PPS
by configuration of the jumpers as indicated in the diagram below (Figure 6-7).
o
If PPS is received via this port, Pin 7 (see Table 6-2) must be driven via a TTL (3.3 V / 5 V)
active high trigger. The pulse duration should be greater than 1 millisecond.
o
$GPZDA (GPS Time) is received via this port and, together with PPS, is essential for system
timing.
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If heading is input via this port, an RS-232 $HEHDT is expected on Pin 3 (Samtec 20 pin)
(see Table 6-2).
The following diagrams show various GNSS interface options: