Novatel GPStation, Руководство пользователя, Страница: 32 / 38

Appendix A - Technical Specifications
24 GPStation™ User Manual
INPUT/OUTPUT STROBES
VARF Output A programmable variable frequency output ranging from 156 Hz - 10.23 MHz
(refer to FREQUENCY_OUT command), with pulse width = 49 ns. This is a
normally high, active low pulse. The time between pulses may vary by as much
as 49 ns jitter.
PPS Output A one-pulse-per-second time synchronization output. This is a normally high,
active low pulse (200
µ
s) where the falling edge is the reference.
Measure Output
20 pulses-per-second output, normally high, active low where the pulse width is
200
µ
s. The falling edge is the receiver measurement strobe.
Mark Input An input mark (negative pulse > 55 ns), time tags output log data to the time of
the falling edge of the mark input pulse (refer to LOG command syntax -
ONMARK). This line is TTL or contact-closure compatible.
Status Output Indicates a valid GPS position solution is available. A high level indicates a valid
solution or that the FIX POSITION command has been set.
Table 4 contains I/O port pin-out information. The electrical specifications of the strobe signals are as follows:
Output Voltage: Standard TTL levels
Sink Current:
Source Current:
64 mA
15 mA
Input
Voltage: Standard TTL levels
Current:
≤
5 mA